MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Talanta' source. Mon, 06 Feb 2012 12:55:20 +0100 http://www.medworm.com/index.php?rid=5656856&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284452%26dopt%3DAbstract Authors: de Morais P, Stoichev T, Basto MC, Vasconcelos MT Abstract Methods for chlorophenols (CPs) determination (with low limits of detection) that can be applied to real environmental samples (waters, sediments, soils, biological tissues) and food are reviewed. Special emphasis is given to sampling, storage conditions and the application of preconcentration techniques for the determination of CPs using chromatographic methods. Solid phase extraction, solid phase microextraction, stir bar sorptive extraction, liquid phase microextraction, dispersive liquid-liquid microextraction, liquid-liquid-liquid microextraction and purge and trap methods are considered. Methods for microwave and ultrasonic extraction of CPs from solid matrices are also focused. PMID: 22284452 [PubMed - i... Talanta journals http://www.medworm.com/rss/comments.php?id=5656856 Mon, 30 Jan 2012 05:00:00 +0100 5656856 http://www.medworm.com/index.php?rid=5656855&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284453%26dopt%3DAbstract Authors: Clémens S, Monperrus M, Donard OF, Amouroux D, Guérin T Abstract Mercury is a toxic compound that can contaminate humans through food and especially via fish consumption. Mercury's toxicity depends on the species, with methylmercury being the most hazardous form for humans. Hg speciation analysis has been and remains a widely studied subject because of the potential difficulty of preserving the initial distribution of mercury species in the analysed sample. Accordingly, many analytical methods have been developed and most of them incur significant loss and/or cross-species transformations during sample preparation. Therefore, to monitor and correct artefact formations, quantification by isotope dilution is increasingly used and provides significant added value for analyt... Talanta journals http://www.medworm.com/rss/comments.php?id=5656855 Mon, 30 Jan 2012 05:00:00 +0100 5656855 http://www.medworm.com/index.php?rid=5656854&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284454%26dopt%3DAbstract Authors: B Lima M, Insausti M, Domini CE, Pistonesi MF, Ugulino de Araújo MC, Fernández Band BS Abstract An automatic method, based on flow-batch (FB), for determining glycerol in biodiesel was developed. The FB systems draw upon the useful features of flow, batch and multi-commutation approaches. The standards and samples preparation, as well as, derivatization and analysis were fully automated. For that purpose, a homemade chamber was built. The proposed method is based on liquid-liquid extraction of glycerol and simultaneous oxidation with periodate, generating formaldehyde that reacts with acetylacetone. A fluorescent product of 3,5-diacetyl-1,4-dihydrolutidine was obtained. The fluorescence signal was recorded at λ(ex)=417nm and λ(em)=514nm. A linear response was observed ... Talanta journals http://www.medworm.com/rss/comments.php?id=5656854 Mon, 30 Jan 2012 05:00:00 +0100 5656854 http://www.medworm.com/index.php?rid=5656853&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284455%26dopt%3DAbstract Authors: Guo Z, Hao T, Duan J, Wang S, Wei D Abstract A novel strategy for the enhancement of electrochemiluminescence (ECL) was developed by combining CdS quantum dots (QDs), graphene (G) and agarose. This enhanced ECL was exploited to develop a label-free ECL immunosensor for the ultrasensitive detection of alpha fetoprotein (AFP). The novel G-CdS QDs-agarose composite was first coated on the glass carbon electrode surface to form a robust film, which exhibited high ECL intensity, good biocompatibility and high stability. After that 3-aminopropyl-triethoxysilane (APS), as a binding linker, was conjugated to the G-CdS QDs-agarose composite film on the electrode, the ECL signal was significantly enhanced. The fabrication of ECL immunosensor was successfully completed by immobilizin... Talanta journals http://www.medworm.com/rss/comments.php?id=5656853 Mon, 30 Jan 2012 05:00:00 +0100 5656853 http://www.medworm.com/index.php?rid=5656852&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284456%26dopt%3DAbstract Authors: Dong KY, Ham DJ, Kang BH, Lee K, Choi J, Lee JW, Choi HH, Ju BK Abstract The effect of plasma treatment on the gas sensing properties of screen-printed single-walled carbon nanotube (SWCNT) pastes is reported. The gas sensors, using SWCNT pastes as a sensing material, were fabricated by photolithography and screen printing. The SWCNT pastes were deposited between interdigitated electrodes on heater membrane by screen printing. In order to functionalize the pastes, they were plasma treated using several gases which produce defects caused by reactive ion etching. The Ar and O(2) plasma-treated SWCNT pastes exhibited a large response to NO(2) exposure and the fluorinated gas, such as CF(4) and SF(6), plasma-treated SWCNT pastes exhibited a large response to NH(3) exposure. ... Talanta journals http://www.medworm.com/rss/comments.php?id=5656852 Mon, 30 Jan 2012 05:00:00 +0100 5656852 http://www.medworm.com/index.php?rid=5656851&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284457%26dopt%3DAbstract In this study, the new C(18)-functionalized ultrafine magnetic silica nanoparticles (C(18)-UMS NPs) were successfully synthesized and applied for extraction of sudan dyes in water samples based on the magnetic solid-phase extraction (MSPE). The extraction and concentration were carried out in one step by blending C(18)-UMS NPs and water samples. The sudan dyes adsorbed C(18)-UMS NPs were isolated from the matrix easily with an external magnetic field. After desorption the quantitation of sudan dyes was done by ultra fast liquid chromatography (UFLC). Satisfactory extraction recovery can be obtained with only 50mgC(18)-UMS NPs. The effects of experimental parameters, including the amount of the nanoparticles, extraction time, pH value, desorption solvent, volume of desorption solvent and de... Talanta journals http://www.medworm.com/rss/comments.php?id=5656851 Mon, 30 Jan 2012 05:00:00 +0100 5656851 http://www.medworm.com/index.php?rid=5656850&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284458%26dopt%3DAbstract Authors: Magiera S, Baranowska I, Kusa J Abstract A sensitive ultra-performance liquid chromatography tandem mass spectrometry method with electrospray ionisation (UHPLC-ESI-MS/MS) was developed for the simultaneous determination of 52 compounds: β-blockers, polyphenols (antioxidants) and their metabolites in mixture of standards and after addition the 52 standard solutions to human urine samples. The analyses of urine samples obtained from patients treated with β-blockers were also carried out. The separation of analytes was performed on a Hypersil GOLD™ column (100mm×2.1mm, 1.9μm) using a gradient elution profile for 10min and mobile phase consisting of 0.1% formic acid in water and acetonitrile. In these conditions, some of the tested compounds were not separated, but this... Talanta journals http://www.medworm.com/rss/comments.php?id=5656850 Mon, 30 Jan 2012 05:00:00 +0100 5656850 http://www.medworm.com/index.php?rid=5656849&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284459%26dopt%3DAbstract Authors: Fan X, Li H, Zhao J, Lin F, Zhang L, Zhang Y, Yao S Abstract A novel label-free and sensitive fluorescent aptasensor for the detection of potassium ion (K(+)) was developed based on the horseradish peroxidase-mimicking DNAzyme (HRP-DNAzyme). In this work, we selected a K(+)-stabilized single stranded DNA (ssDNA) with G-rich sequence as the recognition element. In the presence of K(+), the G-rich DNA folded into the G-quadruplex structure, and then hemin can bind to the G-quadruplex structure as a co-factor and form HRP-DNAzyme. 3-(p-Hydroxyphenyl)-propanoic acid (HPPA) can be oxidized by H(2)O(2) into a fluorescent product in the presence of DNAzyme. The fluorescence intensity of the HPPA oxidative product increased with the K(+) concentration. Under the optimal conditions... Talanta journals http://www.medworm.com/rss/comments.php?id=5656849 Mon, 30 Jan 2012 05:00:00 +0100 5656849 http://www.medworm.com/index.php?rid=5656848&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284460%26dopt%3DAbstract Authors: Companioni-Damas EY, Santos FJ, Galceran MT Abstract This paper proposes a new method for the analysis of linear and cyclic methylsiloxanes in water samples based on headspace-solid phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). The extraction efficiency of four commercially available SPME-fibres was evaluated and it was found that a 65μm polydimethylsiloxane/divinylbenzene (PDMS/DVB) coating was the most suitable for the extraction of siloxanes. The method provided good linearity (r>0.999) and precision (RSD % <17%), and low limits of quantification ranging from 0.01 to 0.74ngL(-1) for linear siloxanes and between 18 and 34ngL(-1) for cyclic siloxanes. The HS-SPME-GC-MS method was applied to the analysis of linear and cycli... Talanta journals http://www.medworm.com/rss/comments.php?id=5656848 Mon, 30 Jan 2012 05:00:00 +0100 5656848 http://www.medworm.com/index.php?rid=5656847&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284461%26dopt%3DAbstract Authors: Jin Y, Luan X, Liu H, Gao C, Li S, Cao D, Li X, Cai Z, Jiang Y Abstract A novel VEGFR-2 and Src dual inhibitor, 6-Chloro-2-methoxy-N-(2-methoxybenzyl) acridin-9-amine (MBAA), is a 9-aminoacridine derivative, but its pharmacokinetics and metabolism in body remain unknown. Using liquid chromatography tandem electrospray ionization mass spectrometry with the multiple reaction monitoring modes, we developed and validated a simple, rapid, sensitive and accurate technology for analyses of MBAA in the rat plasma, urine and bile. The micro samples were quickly prepared by 96-well plate. Chromatographic separation was performed on a C(18) column with gradient elution. High-quality linearity calibration curves were achieved over a concentration range of 1.00-3000ngmL(-1). Intra- and... Talanta journals http://www.medworm.com/rss/comments.php?id=5656847 Mon, 30 Jan 2012 05:00:00 +0100 5656847 http://www.medworm.com/index.php?rid=5656846&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284462%26dopt%3DAbstract Authors: Del Castillo ML, Rodriguez-Valenciano M, de la Peña Moreno F, Blanch GP Abstract A new method based on the use of SPME followed by the MDGC-MS analysis was developed to determine pesticides in fruit juice. Different pesticide mixture standards (i.e. Mix 101, 13 and 164) were initially analyzed to optimize the separation conditions. To evaluate the advantages of the two-dimensional system over monodimensional GC, a comparative study on relative standard deviations, detection limits and correlation coefficients was carried out. As a result, selective transfers of some pesticides from the first to the second dimension were at times essential to avoid overlapping. The selected separation conditions from the study with standards were applied to fruit juices spiked with some pe... Talanta journals http://www.medworm.com/rss/comments.php?id=5656846 Mon, 30 Jan 2012 05:00:00 +0100 5656846 http://www.medworm.com/index.php?rid=5656845&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284463%26dopt%3DAbstract Authors: Zhao L, Zhao Y, Li Q, Chen X, Xiao F, He B, Wang J, Bi K Abstract In order to investigate the preclinical pharmacokinetics of cefuroxime lysine, a fast, sensitive and high throughput UPLC-ESI-MS/MS method has been developed and validated for the quantitative determination of cefuroxime in dog plasma. Cefuroxime and IS phenacetin were extracted from plasma samples by PPT or LLE procedure, and then separated on an ACQUITY UPLC™ BEH C(18) column with an isocratic elution of acetonitrile-0.1% formic acid in 10mM ammonium acetate (40:60, v/v). MRM using the fragmentation transitions of m/z 442→364 and 180→110 in positive ESI mode was performed to quantify cefuroxime and IS, respectively. The calibration curves were linear over the concentration range of 2-400μg/ml for PP... Talanta journals http://www.medworm.com/rss/comments.php?id=5656845 Mon, 30 Jan 2012 05:00:00 +0100 5656845 http://www.medworm.com/index.php?rid=5656844&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284464%26dopt%3DAbstract Authors: Cong W, Liang Q, Li L, Shi J, Liu Q, Feng Y, Wang Y, Luo G Abstract Pirarubicin (THP) is an anthracycline frequently used in the chemotherapy against acute leukemia, malignant lymphoma and several solid tumors. However, its clinical use is severely limited by the development of a progressive dose-dependent cardiomyopathy that results in irreversible congestive heart failure. To provide a strategy for constraining or minimizing the cumulative cardiotoxicity of THP, a pirarubicin liposome powder (L-THP) was appropriately prepared, and the cumulative cardiotoxicity of L-THP and free THP (F-THP) were investigated on Sprague-Dawley rats after 3 successive doses. Urinary samples for metabonomic study, serum samples for biochemical assay, and heart samples for histopathology test... Talanta journals http://www.medworm.com/rss/comments.php?id=5656844 Mon, 30 Jan 2012 05:00:00 +0100 5656844 http://www.medworm.com/index.php?rid=5656843&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284465%26dopt%3DAbstract Authors: Borgese L, Salmistraro M, Gianoncelli A, Zacco A, Lucchini R, Zimmerman N, Pisani L, Siviero G, Depero LE, Bontempi E Abstract This work is presented as an improvement of a recently introduced method for airborne particulate matter (PM) filter analysis [1]. X-ray standing wave (XSW) and total reflection X-ray fluorescence (TXRF) were performed with a new dedicated laboratory instrumentation. The main advantage of performing both XSW and TXRF, is the possibility to distinguish the nature of the sample: if it is a small droplet dry residue, a thin film like or a bulk sample. Another advantage is related to the possibility to select the angle of total reflection to make TXRF measurements. Finally, the possibility to switch the X-ray source allows to measure with more accuracy... Talanta journals http://www.medworm.com/rss/comments.php?id=5656843 Mon, 30 Jan 2012 05:00:00 +0100 5656843 http://www.medworm.com/index.php?rid=5656842&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284466%26dopt%3DAbstract Authors: Justino CI, Freitas AC, Rocha-Santos TA, Duarte AC Abstract A methodology based on optical fiber (OF) sensing was developed to screen single walled carbon nanotubes (SWCNT) in aqueous solutions. This method was validated by the comparison of its analytical performance with that of an ultraviolet-visible (UV-Vis) technique by monitoring the absorbance intensities at 500nm, and no significant difference (p=0.854) was observed between such two methods. The results obtained by the OF sensor were encouraging in what concerns a new approach for detection and quantification of SWCNT in solutions due to its compact design, less expensive materials and equipment, as well as a requirement of low volume of sample. Additionally, it was concluded that the nonlinear calibration model ob... Talanta journals http://www.medworm.com/rss/comments.php?id=5656842 Mon, 30 Jan 2012 05:00:00 +0100 5656842 http://www.medworm.com/index.php?rid=5656841&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284467%26dopt%3DAbstract Authors: Lee Y, Kim J, Lee S, Woo YA, Chung H Abstract Direct transmission Raman measurements for analysis of pharmaceuticals in capsules are advantageous since they can be used to determine active pharmaceutical ingredient (API) concentrations in a non-destructive manner and with much less fluorescence background interference from the capsules themselves compared to conventional back-scattering measurements. If a single calibration model such as developed from spectra simply collected in glass vials could be used to determine API concentrations of samples contained in capsules of different colors rather than constructing individual models for each capsule color, the utility of transmission measurements would be further enhanced. To evaluate the feasibility, transmission Raman spec... Talanta journals http://www.medworm.com/rss/comments.php?id=5656841 Mon, 30 Jan 2012 05:00:00 +0100 5656841 http://www.medworm.com/index.php?rid=5656840&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284468%26dopt%3DAbstract Authors: Ranjbari E, Biparva P, Hadjmohammadi MR Abstract A sensitive, rapid and efficient method for the extraction of quercetin as well as its determination in honey and biological samples was developed using inverted dispersive liquid-liquid microextraction (IDLLME) and HPLC-UV. The extraction method is based on the application of an extracting solvent lighter than water in the ternary component solvent (aqueous solution: extracting solvent: disperser solvent) system. The extraction parameters such as type and volume of extracting and disperser solvent, pH of sample, stirring rate and extraction time were optimized. Under the optimal conditions (extracting solvent: 100μL 1-octanol; disperser solvent: 300μL acetonitrile; pH of sample: 4.5 and stirring rate: 1000rpm) a linear ca... Talanta journals http://www.medworm.com/rss/comments.php?id=5656840 Mon, 30 Jan 2012 05:00:00 +0100 5656840 http://www.medworm.com/index.php?rid=5656839&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284469%26dopt%3DAbstract Authors: Polo-Luque ML, Simonet BM, Valcárcel M Abstract This paper reports for the first time the use of microextraction by packed sorbents in combination with Capillary electrophoresis (CE) for carry out the preconcentration and determination of three characteristics cations of ionic liquids in river water. Before analysis a carbon nanotubes modified filter was used to remove potential organic interferences from the samples. The system was automated by connecting the syringe-microextraction by packed sorbents (MEPS) assembly to a syringe pump and interfacing it to a computer. After preconcentration, analytes were determined by NACE. The limits of quantification of analytes were of 0.02mgL(-1) from only 5mL of sample with an RSD of less than 7%. The values of recovery range betwe... Talanta journals http://www.medworm.com/rss/comments.php?id=5656839 Mon, 30 Jan 2012 05:00:00 +0100 5656839 http://www.medworm.com/index.php?rid=5656838&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284470%26dopt%3DAbstract Authors: Zhou X, Shao X, Shu JJ, Liu MM, Liu HL, Feng XH, Liu F Abstract A novel sol-gel-coated ionic liquid-based ([AMIM][N(SO(2)CF(3))(2)]-OH-TSO) fiber was successfully applied for the determination of phthalate esters (PAEs) in agricultural plastic films by ultrasonic extraction (UE) combined with solid phase microextraction-gas chromatography (SPME-GC) due to its high thermal stability, specific selectivity and extraction efficiency. The extractant for UE and the adsorption time for SPME were optimized to achieve higher extraction efficiency. The desorption temperature and time were also optimized to avoid the carryover effect of previous extraction, and ultimately improve the precision and accuracy of the method. The [AMIM][N(SO(2)CF(3))(2)]-OH-TSO fiber showed comparable, or... Talanta journals http://www.medworm.com/rss/comments.php?id=5656838 Mon, 30 Jan 2012 05:00:00 +0100 5656838 http://www.medworm.com/index.php?rid=5656837&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284471%26dopt%3DAbstract Authors: Yang L, Liu S, Zhang Q, Li F Abstract A simple and effective strategy was proposed for synthesis of AuNPs@polyaniline (AuNPs@PANI) core-shell nanocomposites. AuNPs@PANI nanocomposites were prepared by one-step chemical oxidative polymerization of aniline using chloroaurate acid as the oxidant and AuNPs as the seeds. The synthesized AuNPs@PANI nanocomposites were characterized with transmission electron microscope and UV-vis absorption spectra. Cyclic voltammetric experiments indicated that AuNPs@PANI nanocomposites showed excellent electroactivity in neutral and even alkaline solution. The obtained AuNPs@PANI nanocomposites-modified electrode was fabricated to simultaneously determine dopamine (DA) and ascorbic acid (AA) by differential pulse voltammetry. The separation be... Talanta journals http://www.medworm.com/rss/comments.php?id=5656837 Mon, 30 Jan 2012 05:00:00 +0100 5656837 http://www.medworm.com/index.php?rid=5656836&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284472%26dopt%3DAbstract Authors: Chen Q, Bai S, Lu C Abstract In this work, we utilize the triangular gold nanoparticles (AuNPs) prepared by trisodium citrate reduction of HAuCl(4) in presence of nonionic fluorosurfactant (FSN) as a novel chemiluminescence (CL) probe for the determination of captopril. Captopril can induce a sharp decrease in CL intensity from the triangular AuNPs-catalyzed luminol system. Under the selected experimental conditions, a linear relationship was obtained between the logarithm of CL intensity and the logarithm of concentration of captopril in the range of 23.0-920nM, and the detection limit at a signal-to-noise ratio of 3 for captopril was 4.6nM. The as-prepared triangular AuNPs were easier to synthesize, stable at a wider pH range and high ionic strength, and exhibited a high... Talanta journals http://www.medworm.com/rss/comments.php?id=5656836 Mon, 30 Jan 2012 05:00:00 +0100 5656836 http://www.medworm.com/index.php?rid=5656835&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284473%26dopt%3DAbstract Authors: Jin Y, Chen C, Meng L, Chen J, Li M, Zhu Z Abstract Successful simultaneous enantioseparation and sensitive determination of three β-blockers (PIN, OX and PRO), have been achieved by capillary electrophoresis using an achiral ionic liquid, [GTMA]Cl, as a modifier to cooperate with dual CDs containing DM-β-CD and TM-β-CD. The influence of aIL was investigated in details, including various aILs, the concentration of aIL and molar ratio of aIL to CD. The ratio of DM-β-CD to TM-β-CD in dual CDs was also discussed. DM-β-CD and TM-β-CD favor the enantioseparations of PIN/OX and PRO, respectively. Meanwhile, the presence of [GTMA]Cl was found to play a key role in enantioseparations, and it widened the scope of application of DM-β-CD and TM-β-CD. Furthermore, FESI as an ... Talanta journals http://www.medworm.com/rss/comments.php?id=5656835 Mon, 30 Jan 2012 05:00:00 +0100 5656835 http://www.medworm.com/index.php?rid=5656834&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284474%26dopt%3DAbstract Authors: Dar GN, Umar A, Zaidi SA, Baskoutas S, Hwang SW, Abaker M, Al-Hajry A, Al-Sayari SA Abstract This paper reports a very simple, reliable and facile methodology to fabricate ultra-high sensitive liquid ammonia chemical sensor using well-crystalline hexagonal-shaped ZnO nanopencils as an efficient electron mediator. A low-temperature facile hydrothermal technique was used to synthesize ZnO nanopencils. The synthesized nanopencils were characterized in detail in terms of their morphological, structural and optical properties which confirmed that the synthesized nanomaterial is well-crystalline, possessing wurtzite hexagonal phase and possess very good optical properties. A very high sensitivity of ∼26.58μAcm(-2)mM(-1) and detection limit of ∼5nM with a correlation coeffic... Talanta journals http://www.medworm.com/rss/comments.php?id=5656834 Mon, 30 Jan 2012 05:00:00 +0100 5656834 http://www.medworm.com/index.php?rid=5656833&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284475%26dopt%3DAbstract Authors: Tsoi YK, Ho YM, Leung KS Abstract A novel arsenic-ion imprinted polymer (As-IIP) was firstly synthesized for the separation and recovery of trace elemental As from environmental water samples. Polymers prepared from bifunctional monomers with intrinsic metal-binding capability are a platform for tailoring ion-selectivity via imprinting moiety-template interaction, without complex formation and ligand immobilization. In the present study, As-IIPs based on 1-vinylimidazole, 4-vinylpyridine and styrene were designed to investigate the imprinting mechanism in relation to their structural and functional properties. In terms of selectivity as well as imprinting effects compared with the non-imprinted polymer (NIP), 1-vinylimidazole-based As-IIP exhibited superior analyte recogni... Talanta journals http://www.medworm.com/rss/comments.php?id=5656833 Mon, 30 Jan 2012 05:00:00 +0100 5656833 http://www.medworm.com/index.php?rid=5656832&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284476%26dopt%3DAbstract Authors: Cuello S, Sanz-Landaluze J, Madrid Y, Guinea J, Cámara C Abstract Bioaccumulation and possible transformation of methylmercury and selenite has been checked on a 72h-cycle of bioaccumulation and depuration using larvae from zebrafish. The larvae were exposed to methylmercury and selenite at concentrations of 1% and 0.1% of their LC(50) values. Quantitative extraction of methylmercury and selenite from exposed larvae was achieved by using ultrasonic probe-assisted extraction (USP), thus reducing extraction time and solvent consumption. Extracted species collected at different exposure times were characterized and quantified by liquid chromatography coupled to ICP-MS. Bioconcentration factors (BCFs) were estimated by two procedures: (i) as the ratio of the contaminant conce... Talanta journals http://www.medworm.com/rss/comments.php?id=5656832 Mon, 30 Jan 2012 05:00:00 +0100 5656832 http://www.medworm.com/index.php?rid=5656831&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284477%26dopt%3DAbstract Authors: Ubeda C, Balsera C, Troncoso AM, Callejón RM, Morales ML Abstract A solid phase extraction method (SPE) using Isolute ENV+ cartridges was validated for the determination of ethyl carbamate (EC) in different kinds of vinegars. The method proved to be quite sensitive, precise and accurate, improving the recovery and LQD of other existing methods for the same purpose. For the optimization of the method, different pH values of the sample were tested, resulting 5.5 the most adequate. Among the 14 samples analysed, only 5 of them had contents of EC above the quantification limits, ranging between 6.73μg/L and 56.4μg/L. The highest value was found in red wine vinegar. Taking into account the amount of vinegar consumed in a meal and the limits established for alcoholic beverage... Talanta journals http://www.medworm.com/rss/comments.php?id=5656831 Mon, 30 Jan 2012 05:00:00 +0100 5656831 http://www.medworm.com/index.php?rid=5656830&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284478%26dopt%3DAbstract Authors: Bodade AB, Bodade AB, W.hade HG, Chaudhari GN, Kothari DC Abstract Nanocrystalline 10wt% Ni and 0.2wt% Sm doped CoFe(2)O(4) was prepared by sol-gel citrate method and calcined at different temperatures. The CoFe(2)O(4) nanoparticles were characterized by X-ray diffraction (XRD), electrical properties were studied by impedance analysis. The XRD of CoFe(2)O(4) shows cubic structure with grain growth of 40nm. The ac conductivity was studied for the sample 10wt% Ni and 0.2wt% Sm doped CoFe(2)O(4) calcined at 650°C, at temperature range from 100 to 700°C over a wide range of frequencies from 50Hz to 200kHz. The result indicates that the ac conductivity depend on temperature, frequency and concentration of dopant. Nanocrystalline 10wt% Ni and 0.2wt% Sm doped CoFe(2)O(4) was fo... Talanta journals http://www.medworm.com/rss/comments.php?id=5656830 Mon, 30 Jan 2012 05:00:00 +0100 5656830 http://www.medworm.com/index.php?rid=5656829&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284479%26dopt%3DAbstract Authors: Geng Y, Ding M, Chen H, Li HF, Lin JM Abstract Hydrophilic carbon-functionalized magnetic microspheres coated with chitosan (Fe(3)O(4)@C@CHI) were synthesized for the first time. The hydrophilic carbonaceous layer on the Fe(3)O(4) microspheres was formed by the hydrothermal reaction of Fe(3)O(4) microspheres and glucose, and then chitosan was coated on surface of the carbon-functionalized microspheres by an easy zero-length reaction with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as cross-linkers. The Fe(3)O(4)@C@CHI microspheres were spherical core-shell structure with uniform size at about 400nm. The microspheres had a high saturation magnetization of 60.22emug(-1), which was sufficient for magnetic separation. The Fe(3)O(4)@C@CHI... Talanta journals http://www.medworm.com/rss/comments.php?id=5656829 Mon, 30 Jan 2012 05:00:00 +0100 5656829 http://www.medworm.com/index.php?rid=5656828&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284480%26dopt%3DAbstract Authors: Muratli JM, McManus J, Mix A, Chase Z Abstract Microwave-assisted, hydrofluoric acid digestion is an increasingly common tool for the preparation of marine sediment samples for analysis by a variety of spectrometric techniques. Here we report that analysis of terrigenous-dominated sediment samples occasionally results in anomalously low values for several elements, including Al, Ba, Ca, Mg, and Sr. Measured concentrations of these elements increased with time between sample preparation and sample analysis, reaching stable values after 8-29 days. This lag is explained by the formation and subsequent dissolution of poorly soluble fluoride phases during digestion. Other elements, such as Fe, Mn, and Ti, showed little or no lag and were quickly measurable at a stable value. Fu... Talanta journals http://www.medworm.com/rss/comments.php?id=5656828 Mon, 30 Jan 2012 05:00:00 +0100 5656828 http://www.medworm.com/index.php?rid=5656827&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284481%26dopt%3DAbstract Authors: Lopes RP, Reyes RC, Romero-González R, Frenich AG, Vidal JL Abstract A multiclass method has been optimized and validated for the simultaneous determination of 20 veterinary drug residues belonging to several classes, as quinolones, sulfonamides, macrolides, anthelmintics, avermectins and diamino derivatives, and benzathine, used as a marker of the presence of penicillin, in muscle chicken. It has been based on QuEChERS methodology (quick, easy, cheap, effective, rugged and safe) and ultra high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UHPLC-MS/MS). Several chromatographic conditions were optimized, obtaining a running time <8.5min. The developed method was validated on the basis of international guidelines. Mean recoverie... Talanta journals http://www.medworm.com/rss/comments.php?id=5656827 Mon, 30 Jan 2012 05:00:00 +0100 5656827 http://www.medworm.com/index.php?rid=5656826&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284482%26dopt%3DAbstract Authors: De Bock L, Boussery K, Colin P, De Smet J, T'jollyn H, Van Bocxlaer J Abstract A fast and sensitive UPLC-MS/MS method was developed and validated for the simultaneous quantification of six probe metabolites for the in vitro cytochrome P450 activity determination in hepatic microsomes from patients with hepatic impairment. The metabolites acetaminophen (CYP1A2), 4'-hydroxy-mephenytoin (CYP2C19), 4-hydroxy-tolbutamide (CYP2C9), dextrorphan (CYP2D6), 6-hydroxy-chlorzoxazone (CYP2E1) and 1-hydroxy-midazolam (CYP3A4), together with the internal standard chlorpropamide, were separated on a Waters Acquity UPLC BEH C18 column (50mm×2.1mm, 1.7μm particle size) with VanGuard pre-column (5mm×2.1mm, 1.7μm particle size). A short gradient elution (total run time of 5.25min), using ... Talanta journals http://www.medworm.com/rss/comments.php?id=5656826 Mon, 30 Jan 2012 05:00:00 +0100 5656826 http://www.medworm.com/index.php?rid=5656825&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284483%26dopt%3DAbstract Authors: Pena-Pereira F, Costas-Mora I, Lavilla I, Bendicho C Abstract A rapid and simple screening method for polycyclic aromatic hydrocarbons (PAHs) in water samples is proposed. The method is based on the combination of a miniaturized sample preparation approach, namely, directly suspended droplet microextraction (DSDME), and microvolume fluorospectrometry. Benzo[a]pyrene (BaP) was used as the model compound for screening purposes. Under optimal conditions, a detection limit of 0.024μgL(-1) and an enrichment factor of 159 were obtained for BaP in 5min. The repeatability, expressed as relative standard deviation (RSD), was 4.9% (n=8). The unreliability region of the screening method was 0.54-0.67μgL(-1), by using a cut-off value of 0.6μgL(-1) of BaP. Finally, the proposed meth... Talanta journals http://www.medworm.com/rss/comments.php?id=5656825 Mon, 30 Jan 2012 05:00:00 +0100 5656825 http://www.medworm.com/index.php?rid=5656824&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284484%26dopt%3DAbstract Authors: Manley M, McGoverin CM, Engelbrecht P, Geladi P Abstract Near infrared hyperspectral imaging (NIR-HSI) allows spatially resolved spectral information to be collected without sample destruction. Although NIR-HSI is suitable for a broad range of samples, sizes and shapes, topography of a sample affects the quality of near infrared (NIR) measurements. Single whole kernels of three cereals (barley, wheat and sorghum), with varying topographic complexity, were examined using NIR-HSI. The influence of topography (sample shape and texture) on spectral variation was examined using principal component analysis (PCA) and classification gradients. The greatest source of variation for all three grain types, despite spectral preprocessing with standard normal variate (SNV) transformati... Talanta journals http://www.medworm.com/rss/comments.php?id=5656824 Mon, 30 Jan 2012 05:00:00 +0100 5656824 http://www.medworm.com/index.php?rid=5656823&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284485%26dopt%3DAbstract Authors: Pascale M, Panzarini G, Visconti A Abstract European intake estimates indicate that the presence of HT-2 and T-2 toxins in cereals, mainly in oats, can be of concern for human health. Therefore, the development of sensitive, rapid and reliable methods for determining these mycotoxins in cereals, in particular oats, has high priority. A rapid ultra-performance liquid chromatographic (UPLC) method has been developed for the simultaneous determination of HT-2 and T-2 toxins in oats and wheat at μgkg(-1) level. Ground samples were extracted with methanol/water (90:10, v/v) and the diluted extracts were cleaned up through immunoaffinity columns. HT-2 and T-2 toxins were separated and quantified by UPLC with photodiode array (PDA) detector (λ=202nm) in less than 5min. Mean rec... Talanta journals http://www.medworm.com/rss/comments.php?id=5656823 Mon, 30 Jan 2012 05:00:00 +0100 5656823 http://www.medworm.com/index.php?rid=5656822&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284486%26dopt%3DAbstract This study developed and validated a method of measuring the feminizing chemicals 4-tert-octylphenol, 4-nonylphenol, nonylphenol monoethoxycarboxylate (NP(1)EC), nonylphenol monoethoxylate (NP(1)EO), nonylphenol diethoxylate (NP(2)EO), estrone, 17β-estradiol, estriol, 17α-ethinyl estradiol and bisphenol A in river water, sediment, and tissue using ultra-high performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS) and isotope-dilution techniques. Water samples were pretreated using disk-type automated solid-phase extraction (SPE). Solid samples of sediment, fish, and clams were treated with matrix solid-phase dispersion (MSPD) using C(8) adsorbent. Eluents were directly passed following alumina cartridges for cleanup. The signal intensity of analytes on electrospray ioniz... Talanta journals http://www.medworm.com/rss/comments.php?id=5656822 Mon, 30 Jan 2012 05:00:00 +0100 5656822 http://www.medworm.com/index.php?rid=5656821&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284487%26dopt%3DAbstract Authors: Park TJ, Lee SJ, Kim DK, Heo NS, Park JY, Lee SY Abstract An active immobilization method utilizing the metal-binding property was developed and examined for its ability to facilitate the biosensing of avian influenza virus. The special biosensing performance with optical plasmonic analysis, including surface plasmon resonance (SPR) was evaluated on gold substrate and also by SPR imaging (SPRi) and localized SPR (LSPR) system where antigen-antibody interaction occurs. A complete optical analytical system was developed by integrating microarray and fabricating nanoparticles onto a single glass chip, thus allowing specific and sensitive diagnosis with subsequent binding. Reaction condition for the maximum reactivity was optimized by SPR analysis and more sensitive interactio... Talanta journals http://www.medworm.com/rss/comments.php?id=5656821 Mon, 30 Jan 2012 05:00:00 +0100 5656821 http://www.medworm.com/index.php?rid=5656820&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284488%26dopt%3DAbstract In this study, based on ion-current rectification in the conically shaped nanochannel embedded in polyethylene terephthalate (PET) membrane, we have selectively discriminated three small biomolecules. Because three positive biomolecules (Hoechst 33342, Propidium and Bupivacaine) have different hydrophobicities, their interactions with inside wall of the conical nanochannel are different and their binding affinities can be derived from Langmuir absorption model. Therefore, we can successfully discriminate these small biomolecules. The highest binding constant was obtained for the small molecule with highest hydrophobicity. Another interesting result is that the detection limit for the small molecule with the highest binding constant shifts to submicromole. PMID: 22284488 [PubMed - in pr... Talanta journals http://www.medworm.com/rss/comments.php?id=5656820 Mon, 30 Jan 2012 05:00:00 +0100 5656820 http://www.medworm.com/index.php?rid=5656819&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284489%26dopt%3DAbstract Authors: Yu Y, Wu L Abstract Endocrine disrupting compounds (EDCs) and pharmaceuticals and personal care products (PPCPs) have been acknowledged as emerging pollutants due to widespread contamination in environment. A rapid and reliable analytical method, based on ultrasonic extraction, clean up on Envi-carb cartridge, derivatized with N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA), and analyzed by gas chromatography-mass spectrometry (GC-MS), was developed for determination of 4 EDCs (bisphenol A, estrone, nonylphenol and octylphenol) and 10 PPCPs (acetylsalicylic acid, carbamazepine, clofibric acid, diclofenac, gemfibrozil, ibuprofen, ketoprofen, naproxen, paracetamol and triclosan) in sewage sludge. Mean recoveries of the target analytes, at different spike level... Talanta journals http://www.medworm.com/rss/comments.php?id=5656819 Mon, 30 Jan 2012 05:00:00 +0100 5656819 http://www.medworm.com/index.php?rid=5656818&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284490%26dopt%3DAbstract Authors: Kulchat S, Chaicham A, Ekgasit S, Tumcharern G, Tuntulani T, Tomapatanaget B Abstract The sensor molecule, F-oBOH, containing boronic acid-linked hydrazide and fluorescein moieties was synthesized. For anion sensing applications, F-oBOH was studied in aqueous media. Unfortunately, F-oBOH was found to be hydrolyzed in water. Therefore, a new strategy was developed to prevent the hydrolysis of F-oBOH by applying self-assembly coordination nanoparticles network (F-oBOH-AMP/Gd(3+) CNPs). Interestingly, the nanaoparticles network displayed the enhancement of fluorescent signal after adding Cu(2+) following by CN(-). The network, therefore, possessed a high selectivity for detection of CN(-) compared to other competitive anions in the presence of Cu(2+). Cyanide ion could promot... Talanta journals http://www.medworm.com/rss/comments.php?id=5656818 Mon, 30 Jan 2012 05:00:00 +0100 5656818 http://www.medworm.com/index.php?rid=5656817&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284491%26dopt%3DAbstract Authors: Lv YK, Ma Y, Zhao XB, Jia CL, Sun HW Abstract A high-density imprinted polymeric membrane was immobilized on a porous silica-gel support by polymerization of methacrylic acid with vinyl-silanized silica gel for the selective solid-phase extraction (SPE) of norfloxacin (NOR) in fish samples. The imprinted membranes showed high adsorption capacity (423.2μmolg(-1)), significant selectivity (k=14.64, k'=9.61) and good site accessibility (2h) for NOR. The conditions of SPE were investigated, and water (pH=6), methanol:water (1:1, v/v) and methanol-acetic acid-trifluoroacetic acid (90:9:1, v/v) were selected as the sample solvent, the washing solution and the eluting solution, respectively. Under the optimal SPE condition, three fluoroquinolone residues in fish were separated a... Talanta journals http://www.medworm.com/rss/comments.php?id=5656817 Mon, 30 Jan 2012 05:00:00 +0100 5656817 http://www.medworm.com/index.php?rid=5656816&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284492%26dopt%3DAbstract Authors: Dias Fde S, Bonsucesso JS, Oliveira LC, Dos Santos WN Abstract In the present study, a minicolumn of sisal fiber loaded with alizarin fluorine blue is proposed as a preconcentratio system for copper determination in tobacco leaf samples by flame atomic absorption spectrometry. During the optimization procedure, a two level full factorial design (2(4)) was used at the preliminary evaluation of four factors, involving the following variables: sampling flow rate, elution flow rate, buffer concentration and pH. Regarding the studied levels, this design has shown that buffer concentration and pH were significant factors. The experimental conditions established in the optimization step were: pH=4.75, buffer concentration of 0.005molL(-1) for elution with HCl 1.0molL(-1) this sys... Talanta journals http://www.medworm.com/rss/comments.php?id=5656816 Mon, 30 Jan 2012 05:00:00 +0100 5656816 http://www.medworm.com/index.php?rid=5656815&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284493%26dopt%3DAbstract Authors: Zhao Y, Zheng J, Fang L, Lin Q, Wu Y, Xue Z, Fu F Abstract A environment-friendly microwave-assisted extraction used to extract trace mercury compounds from fish samples, and a ultra-sensitive method for the analysis of Hg(II), methylmercury (MeHg) and ethylmercury (EtHg) by using capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICP-MS) were described in this study. The extraction method is environment-friendly, simple, effective, and can be used to extract trace mercury compounds in fish samples with a satisfied recovery within several minutes. The CE-ICP-MS analytical method has a detection limit as lower as 0.021-0.032ng Hg/mL for MeHg, EtHg and Hg(II), and can be used to determined ultratrace MeHg, EtHg and Hg(II) in natural water and fish sam... Talanta journals http://www.medworm.com/rss/comments.php?id=5656815 Mon, 30 Jan 2012 05:00:00 +0100 5656815 http://www.medworm.com/index.php?rid=5656814&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284494%26dopt%3DAbstract Authors: Ghasemi-Varnamkhasti M, Mohtasebi SS, Rodriguez-Mendez ML, Gomes AA, Araújo MC, Galvão RK Abstract This work proposes a method for monitoring the ageing of beer using near-infrared (NIR) spectroscopy and chemometrics classification tools. For this purpose, the Successive Projections Algorithm (SPA) is used to select spectral variables for construction of Linear Discriminant Analysis (LDA) classification models. A total of 83 alcoholic and non-alcoholic beer samples packaged in bottles and cans were examined. To simulate a long storage period, some of the samples were stored in an oven at 40°C, in the dark, during intervals of 10 and 20 days. The NIR spectrum of these samples in the range 12,500-5405cm(-1) was then compared against those of the fresh samples. The results... Talanta journals http://www.medworm.com/rss/comments.php?id=5656814 Mon, 30 Jan 2012 05:00:00 +0100 5656814 http://www.medworm.com/index.php?rid=5656813&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284495%26dopt%3DAbstract Authors: Van den Eede N, Dirtu AC, Ali N, Neels H, Covaci A Abstract A new method was optimized for the simultaneous determination of several flame retardants (FRs) in indoor dust, namely polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), novel brominated flame retardants (NBFRs) and organophosphate ester flame retardants (OPFRs). The method was based on two previously validated analytical methods for NBFRs and OPFRs, which were combined in order to include even a large number of FRs. An ultrasonic extraction method and two-stage clean-up by adsorption chromatography was optimized using an indoor dust standard reference material (SRM 2584). The 1st cleanup step was essential for fractionation of analytes in the dust extracts, while the 2nd step was important f... Talanta journals http://www.medworm.com/rss/comments.php?id=5656813 Mon, 30 Jan 2012 05:00:00 +0100 5656813 http://www.medworm.com/index.php?rid=5656812&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284496%26dopt%3DAbstract Authors: Dupont AL, Seemann A, Lavédrine B Abstract A methodology for capillary electrophoresis/electrospray ionisation mass spectrometry (CE/ESI-MS) was developed for the simultaneous analysis of degradation products from paper among two families of compounds: low molar mass aliphatic organic acids, and aromatic (phenolic and furanic) compounds. The work comprises the optimisation of the CE separation and the ESI-MS parameters for improved sensitivity with model compounds using two successive designs of experiments. The method was applied to the analysis of lignocellulosic paper at different stages of accelerated hygrothermal ageing. The compounds of interest were identified. Most of them could be quantified and several additional analytes were separated. PMID: 22284496 [PubM... Talanta journals http://www.medworm.com/rss/comments.php?id=5656812 Mon, 30 Jan 2012 05:00:00 +0100 5656812 http://www.medworm.com/index.php?rid=5656811&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284497%26dopt%3DAbstract Authors: Sanvicens N, Varela B, Ballesteros B, Marco MP Abstract Heterologous immunization has proven to be useful to enhance the selectivity and specificity of catalytic antibodies. However, in the field of immunoassays, few studies have been done to establish how the immunization protocol influences the antibody characteristics. In the present study, we have developed an enzyme-linked immunosorbent assay (ELISA) for the detection of the pesticide terbutryn following a homologous and a heterologous immunization strategy. No significant differences have been observed between the immunization procedures regarding immunoassay sensitivity and selectivity. Thus, immunoassays with a limit of detection below the 25ng/l established by current European regulations have been obtained with b... Talanta journals http://www.medworm.com/rss/comments.php?id=5656811 Mon, 30 Jan 2012 05:00:00 +0100 5656811 http://www.medworm.com/index.php?rid=5656810&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284498%26dopt%3DAbstract Authors: Xiong C, Ling L Abstract A label-free method for sensitive detection of Hg(2+) was developed with gold nanoparticles (AuNPs) by using dynamic light scattering (DLS) technique. Oligonucleotide 5'-TTT CTT CTT CGT TGT TGT TT-3' could transform from uncoil to rigid duplex or hairpin structure upon addition of Hg(2+) ions, which was confirmed by experiments of fluorescence resonance energy transfer and change of melting temperature. The change of DNA structure reduced its adsorption ability on the surface of AuNPs, and resulted in the aggregation of AuNPs in the salt solution, which could be estimated with average hydrodynamic diameter by using DLS technique. Under the optimum conditions, the average diameter increased linearly with the concentration of Hg(2+) over the range fr... Talanta journals http://www.medworm.com/rss/comments.php?id=5656810 Mon, 30 Jan 2012 05:00:00 +0100 5656810 http://www.medworm.com/index.php?rid=5656809&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284499%26dopt%3DAbstract Authors: Camino-Sánchez FJ, Zafra-Gómez A, Cantarero-Malagón S, Vílchez JL Abstract A multi-residue method for the analysis of semi-volatile organic pollutants in inland groundwater (river water) at ultra-trace levels in compliance with the European Water Framework Directive (WFD) has been developed and validated by stir bar sorptive extraction (SBSE) and thermal desorption coupled with gas chromatography-triple quadrupole mass spectrometry (SBSE-TD-GC-MS/MS(QqQ)). The method includes various families of compounds included in the WFD and other compounds listed as persistent organic pollutants that are banned in the Stockholm Convention of Persistent Organic Pollutants, such as polychlorinated biphenyls, polycyclic aromatics hydrocarbons, and other pesticides not included in the... Talanta journals http://www.medworm.com/rss/comments.php?id=5656809 Mon, 30 Jan 2012 05:00:00 +0100 5656809 http://www.medworm.com/index.php?rid=5656808&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284500%26dopt%3DAbstract Authors: Hu XZ, Chen ML, Gao Q, Yu QW, Feng YQ Abstract Benzimidazole drugs (BZDs) comprise a large number of synthetic anthelmintics, which are widely used in food-producing animals for prophylactic and therapeutic purposes. To protect consumers from the risks related to BZDs residues, a simple, rapid, and efficient method for simultaneous determination of ten BZDs in animal tissues samples was developed. This analytical procedure involved extracting samples with magnetic solid-phase extraction (MSPE) using magnetite/silica/poly (methacrylic acid-co-ethylene glycol dimethacrylate) (Fe(3)O(4)/SiO(2)/poly (MAA-co-EGDMA)) magnetic microspheres, and determination by capillary zone electrophoresis (CZE). To improve the sensitivity of the method, we employed the electrokinetic injection... Talanta journals http://www.medworm.com/rss/comments.php?id=5656808 Mon, 30 Jan 2012 05:00:00 +0100 5656808 http://www.medworm.com/index.php?rid=5656807&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284501%26dopt%3DAbstract Authors: Silva MA, Ferreira MH, Braga JW, Sena MM Abstract This paper proposes a new method for determination of amoxicillin in pharmaceutical suspension formulations, based on transflectance near infrared (NIR) measurements and partial least squares (PLS) multivariate calibration. A complete methodology was implemented for developing the proposed method, including an experimental design, data preprocessing by using multiple scatter correction (MSC) and outlier detection based on high values of leverage, and X and Y residuals. The best PLS model was obtained with seven latent variables in the range from 40.0 to 65.0mgmL(-1) of amoxicillin, providing a root mean square error of prediction (RMSEP) of 1.6mgmL(-1). The method was validated in accordance with Brazilian and international... Talanta journals http://www.medworm.com/rss/comments.php?id=5656807 Mon, 30 Jan 2012 05:00:00 +0100 5656807 http://www.medworm.com/index.php?rid=5656806&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284502%26dopt%3DAbstract Authors: Godlewska-Żyłkiewicz B, Zambrzycka E, Leśniewska B, Wilczewska AZ Abstract A new ion imprinted polymer (IIP) for ruthenium recognition/pre-concentration was prepared via bulk polymerization using methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking agent in the presence of Ru(III)-allyl acetoacetate complex as a template. The synthesized IIP was used as a new support for solid phase extraction (SPE) of ruthenium from environmental samples before electrothermal atomic absorption spectrometric determination. Variables affecting the SPE process, such as pH, load and elution flow rates, as well as concentration and volume of the eluting solution, were evaluated. The optimized procedure consists of a sample loading (sample pH of ... Talanta journals http://www.medworm.com/rss/comments.php?id=5656806 Mon, 30 Jan 2012 05:00:00 +0100 5656806 http://www.medworm.com/index.php?rid=5656805&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284503%26dopt%3DAbstract Authors: Silva CL, Passos M, Câmara JS Abstract A sensitive assay to identify volatile organic metabolites (VOMs) as biomarkers that can accurately diagnose the onset of breast cancer using non-invasively collected clinical specimens is ideal for early detection. Therefore the aim of this study was to establish the urinary metabolomic profile of breast cancer patients and healthy individuals (control group) and to explore the VOMs as potential biomarkers in breast cancer diagnosis at early stage. Solid-phase microextraction (SPME) using CAR/PDMS sorbent combined with gas chromatography-mass spectrometry was applied to obtain metabolomic information patterns of 26 breast cancer patients and 21 healthy individuals (controls). A total of seventy-nine VOMs, belonging to distinct chemi... Talanta journals http://www.medworm.com/rss/comments.php?id=5656805 Mon, 30 Jan 2012 05:00:00 +0100 5656805 http://www.medworm.com/index.php?rid=5656804&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284504%26dopt%3DAbstract Authors: Mamani Moreno C, Stadler T, da Silva AA, Barbosa LC, de Queiroz ME Abstract In recent years, the release of information about the preventative and curative properties of garlic on different diseases and their benefits to human health has led to an increase in the consumption of garlic. To meet the requirements of international markets and reach competitiveness and profitability, farmers seek to extend the offer period of fresh garlic by increasing post-harvest life. As a result, the use of maleic hydrazide (1,2-dihydropyridazine-3,6-dione) [MH], a plant growth regulator, has been widespread in various garlic growing regions of the world. The present work was undertaken to develop and validate a new analytical procedure based on MH extraction from garlic previously frozen b... Talanta journals http://www.medworm.com/rss/comments.php?id=5656804 Mon, 30 Jan 2012 05:00:00 +0100 5656804 http://www.medworm.com/index.php?rid=5656803&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284505%26dopt%3DAbstract The objective was to offer an alternative to conventional sample treatments, which invariably involve extractions with large solvent volumes followed by clean-up with expensive, not recyclable and limited storage stability immunoaffinity sorbents. The method involved the stirring of 300mg of dried vine fruit subsamples with 400μL of a supramolecular solvent (SUPRAS) made up of decanoico acid/tetrabutylammonium decanoate vesicles. Then, the sample was centrifuged for 15min and OTA was quantified in the extract by liquid chromatography/fluorescence detection against solvent-based calibration curves. Neither dilution nor further clean-up steps of extracts were needed. Quantitation of OTA was interference-free and recoveries ranged between 95% and 101%. The precision of the method, expressed ... Talanta journals http://www.medworm.com/rss/comments.php?id=5656803 Mon, 30 Jan 2012 05:00:00 +0100 5656803 http://www.medworm.com/index.php?rid=5656802&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284506%26dopt%3DAbstract Authors: Wang H, Chung-Davidson YW, Li K, Scott AM, Li W Abstract A rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for simultaneous quantification of three monoamine neurotransmitters (NTs) and melatonin in sea lamprey brain tissues. Separation was performed on a reversed-phase column with mobile phases of 1mM perfluoroheptanoic acid (PFHA) water solution/acetonitrile and mass spectra were acquired in positive electrospray ionization multiple reaction monitoring (MRM) mode. Solid-phase extraction (SPE) was employed to purify and extract the target compounds from the tissue samples. The matrix effects as well as the influence of two extraction methods, protein precipitation (PPT) and SPE, on matrix effects were examined for the fir... Talanta journals http://www.medworm.com/rss/comments.php?id=5656802 Mon, 30 Jan 2012 05:00:00 +0100 5656802 http://www.medworm.com/index.php?rid=5656801&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284507%26dopt%3DAbstract Authors: Zhang Q, Ren Q, Miao Y, Yuan J, Wang K, Li F, Han D, Niu L Abstract A simple, inexpensive, one-step synthesis of graphene/PAA-Au nanocomposites was achieved by using polyallylamine (PAA) as a reducing and stabilizing agent. The synthetic process was carried out only in aqueous solution, which is versatile and environmentally friendly. The resulting nanocomposites could be dispersed into water stably without any additional protection by polymeric or surfactant stabilizers. The products were further characterized by UV-visible absorption spectroscopy, transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR) and photoelectron spectroscopy (XPS). The results indicate that graphene sheets played an important role as a support material to increase t... Talanta journals http://www.medworm.com/rss/comments.php?id=5656801 Mon, 30 Jan 2012 05:00:00 +0100 5656801 http://www.medworm.com/index.php?rid=5656800&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284508%26dopt%3DAbstract Authors: Salinas MR, de la Hoz KS, Zalacain A, Lara JF, Garde-Cerdán T Abstract A method has been developed to analyse the glycosidic aroma precursor of non aromatic red grapes in terms of glucose GG. Due to the matrix interferences, an extract free of glycosylated polyphenols (especially anthocyanins and flavonols) and free glucose has been prepared. Such interferences have been eliminated by combining the use of Oasis MCX SPE and Fehling reagent. The glycosyl aroma precursor's fraction was subjected to an acidic hydrolysis (pH 1, 100°C, 1h), where equimolecular proportions of glucose (glucose GG) were released from their respective aglycones and quantified HPLC-IR. Compared with methods that require detailed analysis of the volatile aglycones, this one is able to estimate with ... Talanta journals http://www.medworm.com/rss/comments.php?id=5656800 Mon, 30 Jan 2012 05:00:00 +0100 5656800 http://www.medworm.com/index.php?rid=5656799&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284509%26dopt%3DAbstract Authors: Zhang HJ, Zheng HZ, Long YJ, Xiao GF, Zhang LY, Wang QL, Gao M, Bai WJ Abstract Because amyloidogenic proteins, such as prion protein, β-amyloid peptide and α-synuclein, are associated with a variety of diseases, methods for their detection are important. Recombinant prion protein (rPrP) can selectively induce aggregation of dihydrolipoic acid capped gold nanoparticles (DHLA-AuNPs), which reduces the absorbance of the DHLA-AuNPs and changes their color from red to blue. These changes were used for label-free qualitative and quantitative detection of amyloidogenic protein. The addition of NaCl improved the detection sensitivity considerably, and the detection limit was as low as 33pmol/L. PMID: 22284509 [PubMed - in process] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=5656799 Mon, 30 Jan 2012 05:00:00 +0100 5656799 http://www.medworm.com/index.php?rid=5656798&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284510%26dopt%3DAbstract Authors: Le-Minh N, Stuetz RM, Khan SJ Abstract A highly sensitive method for the analysis of six sulfonamide antibiotics (sulfadiazine, sulfathiazole, sulfapyridine, sulfamerazine, sulfamethazine and sulfamethoxazole), two sulfonamide metabolites (N(4)-acetyl sulfamethazine and N(4)-acetyl sulfamethoxazole) and the commonly co-applied antibiotic trimethoprim was developed for the analysis of complex wastewater samples. The method involves solid phase extraction of filtered wastewater samples followed by liquid chromatography-tandem mass spectral detection. Method detection limits were shown to be matrix-dependant but ranged between 0.2 and 0.4ng/mL for ultrapure water, 0.4 and 0.7ng/mL for tap water, 1.4 and 5.9ng/mL for a laboratory-scale membrane bioreactor (MBR) mixed liquor, 0... Talanta journals http://www.medworm.com/rss/comments.php?id=5656798 Mon, 30 Jan 2012 05:00:00 +0100 5656798 http://www.medworm.com/index.php?rid=5656797&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284511%26dopt%3DAbstract Authors: Ye Y, Kong T, Yu X, Wu Y, Zhang K, Wang X Abstract A nonenzymatic hydrogen peroxide (H(2)O(2)) sensor was fabricated using the reduced graphene oxide (RGO) and ferroferric oxide (Fe(3)O(4)) nanocomposites as the sensing material. The nanocomposites were synthesized by coprecipitation method and characterized by high-resolution transmission electron microscopy and X-ray diffraction. Results showed that the RGO sheet was evenly decorated by the well-crystallized Fe(3)O(4) nanoparticles. The nanocomposites showed enhanced catalytic ability to the reduction of hydrogen peroxide compared with the RGO, Fe(3)O(4) nanoparticles alone and the mixture materials. The sensor has a quite wide linear range from 0.1mM to 6mM (R(2)=0.990) with less than 5s response time. Moreover, its det... Talanta journals http://www.medworm.com/rss/comments.php?id=5656797 Mon, 30 Jan 2012 05:00:00 +0100 5656797 http://www.medworm.com/index.php?rid=5656796&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284512%26dopt%3DAbstract Authors: Wang J, Zhao WW, Tian CY, Xu JJ, Chen HY Abstract Aiming to find an alternative electrochemiluminescence (ECL) quenching route of high efficiency, biocatalytic precipitation (BCP) was firstly coupled with ECL for investigating its insulating effect on ECL. Experimental data revealed that an insulating layer could be formed via BCP onto the electrode surface, inhibiting the reaction between the coreactant and luminophore and thereby impairing the ECL emission dramatically. Since the extent of insulating effect associated strongly with analyte concentration, a new ECL biosensor was successfully realized. In a model horseradish peroxidase (HRP)-based system, the fabricated biosensor possessed high sensitivity and wide linear range from 1.0×10(-10)M to 1.0×10(-6)M for H(2)O(... Talanta journals http://www.medworm.com/rss/comments.php?id=5656796 Mon, 30 Jan 2012 05:00:00 +0100 5656796 http://www.medworm.com/index.php?rid=5656795&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284513%26dopt%3DAbstract Authors: Shen L, Sun Y, Li J, Chen L, Li L, Zou G, Zhang X, Jin W Abstract In this paper, we reported an ultrasensitive ECL spectrometry for determination of DNA using magnetic streptavidin-coated nanobeads MNBs (SA-MNBs) as the carrier of Ru(bpy)(3)(2+)-NHS, where bpy=2,2'-bipyridyl and NHS=N-hydroxysuccinimide ester, to amplify signal. The SA-MNBs were conjugated to the hybrids consisting of capture DNA, target DNA (t-DNA) and probe DNA immobilized on a substrate, followed by releasing the SA-MNBs and binding a huge number of Ru(bpy)(3)(2+)-NHS to the SA-MNBs. The SA-MNBs with Ru(bpy)(3)(2+)-NHS were immobilized on an Au film electrode by means of a magnet. In the presence of tri-n-propylamine, the ECL spectrum of the Ru(bpy)(3)(2+)-NHS at 1.35V was acquired by using an optical m... Talanta journals http://www.medworm.com/rss/comments.php?id=5656795 Mon, 30 Jan 2012 05:00:00 +0100 5656795 http://www.medworm.com/index.php?rid=5656794&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284514%26dopt%3DAbstract Authors: He L, Zhang M, Zhao W, Liu J, Jiang X, Zhang S, Qu L Abstract A new high-performance liquid chromatography stationary phase has been prepared by covalently bonding 14-membered tetraazamacrocycle to silica gel using γ-chloropropyltrimethoxylsilane as coupling agent. The structure of the new material was characterized by infrared spectroscopy and elemental analysis. With 32 solutes including aromatic and aliphatic compounds, the linear solvation energy relationship method was successfully used to chromatographically evaluate the new phase in reversed phase mode. The retention property of the new phase shows evident similarity with that of ODS stationary phase, as well as distinctive, unique retention characteristics. The separations of n-alkylbenzene, carbamate and organoph... Talanta journals http://www.medworm.com/rss/comments.php?id=5656794 Mon, 30 Jan 2012 05:00:00 +0100 5656794 http://www.medworm.com/index.php?rid=5656793&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284515%26dopt%3DAbstract Authors: Beer S, Müller G, Wöllenstein J Abstract Detection of trace explosives residues at people and cargo control points has become a key security challenge. A severe obstacle is that all commercial and military high explosives have low to extremely low vapor pressures which make them very hard to detect. With detectable vapors not being present, explosives detection needs to proceed through a series of sequential steps including particle collection, thermal vapor conversion and vapor detection. The present paper describes the design and test of an electrostatic particle precipitator which allows particle residue to be collected from the environment, the collected particle residue to be separated into high- and low-electron affinity fractions and the high-electron-affinity one... Talanta journals http://www.medworm.com/rss/comments.php?id=5656793 Mon, 30 Jan 2012 05:00:00 +0100 5656793 http://www.medworm.com/index.php?rid=5656792&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284516%26dopt%3DAbstract Authors: Naggar AH, Elkaoutit M, Naranjo-Rodriguez I, El-Sayed Ael-A, de Cisneros JL Abstract Sonogel-Carbon electrode (SngCE) modified with bentonite (BENT) shows an interesting alternative electrode to be used in the determination of 1,4-benzodiazepines by square wave adsorptive cathodic stripping voltammetry (SWAdCSV). Diazepam (DZ) and chlordiazepoxide hydrochloride (CPZ), were determined using SngCE modified by 5% BENT. An electrochemical study of different parameters (such as pH, buffer type, ionic strength, accumulation potential, scan rate, and accumulation time) which affect the determination of DZ and CPZ is reported. Linear concentration ranges of 0.028-0.256μgmL(-1) DZ (r=0.9997) and 0.034-0.302μgmL(-1) CPZ (r=0.9997) are successfully obtained after an accumulation ti... Talanta journals http://www.medworm.com/rss/comments.php?id=5656792 Mon, 30 Jan 2012 05:00:00 +0100 5656792 http://www.medworm.com/index.php?rid=5656791&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284517%26dopt%3DAbstract Authors: Bagheri A, Behbahani M, Amini MM, Sadeghi O, Taghizade M, Baghayi L, Salarian M Abstract A novel sorbent for simultaneous separation of cadmium and copper was prepared by functionalizing SBA-15 nanoporous silica with diphenylcarbazide. A solid-phase extraction method using the above sorbent has been developed to separate and concentrate trace amount of cadmium and copper ions from environmental samples by flame atomic absorption spectrophotometry measurements. The optimum experimental conditions such as pH, flow rates, type and the smallest amount of eluent for elution of cadmium and copper ions, break through volume and effect of coexisting ions on the separation and determination of cadmium and copper ions were evaluated. The extraction efficiency for cadmium and copper ... Talanta journals http://www.medworm.com/rss/comments.php?id=5656791 Mon, 30 Jan 2012 05:00:00 +0100 5656791 http://www.medworm.com/index.php?rid=5656790&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284518%26dopt%3DAbstract Authors: Franquelo ML, Duran A, Castaing J, Arquillo D, Perez-Rodriguez JL Abstract This paper presents the novel application of recently developed analytical techniques to the study of paint layers on sculptures that have been restored/repainted several times across centuries. Analyses were performed using portable XRF, μ-XRD and μ-Raman instruments. Other techniques, such as optical microscopy, SEM-EDX and μ-FTIR, were also used. Pigments and other materials including vermilion, minium, red lac, ivory black, lead white, barium white, zinc white (zincite), titanium white (rutile and anatase), lithopone, gold and brass were detected. Pigments from both ancient and modern times were found due to the different restorations/repaintings carried out. μ-Raman was very useful to chara... Talanta journals http://www.medworm.com/rss/comments.php?id=5656790 Mon, 30 Jan 2012 05:00:00 +0100 5656790 http://www.medworm.com/index.php?rid=5656789&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284519%26dopt%3DAbstract Authors: Shakeri Yekta S, Gustavsson J, Svensson BH, Skyllberg U Abstract The effect of sequential extraction of trace metals on sulfur (S) speciation in anoxic sludge samples from two lab-scale biogas reactors augmented with Fe was investigated. Analyses of sulfur K-edge X-ray absorption near edge structure (S XANES) spectroscopy and acid volatile sulfide (AVS) were conducted on the residues from each step of the sequential extraction. The S speciation in sludge samples after AVS analysis was also determined by S XANES. Sulfur was mainly present as FeS (∼60% of total S) and reduced organic S (∼30% of total S), such as organic sulfide and thiol groups, in the anoxic solid phase. Sulfur XANES and AVS analyses showed that during first step of the extraction procedure (the removal... Talanta journals http://www.medworm.com/rss/comments.php?id=5656789 Mon, 30 Jan 2012 05:00:00 +0100 5656789 http://www.medworm.com/index.php?rid=5656788&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284520%26dopt%3DAbstract Authors: Zamora D, Blanco M, Bautista M, Mulero R, Mir M Abstract The excellent compatibility of polyol esters (POEs) with general fluids coolants such as CO(2) and non-chlorinated coolants (e.g. hydrofluorocarbons, HFCs) in terms of solubility, miscibility and chemical stability has fostered their use as lubricants by the refrigeration industry. The most widely used POEs bases consist of esters of polyalcohols - such as pentaerythritol, dipentaerythritol and neopentylglycol - with mixtures of carboxylic acids of 4-10 carbon atoms. Their thermophysical properties (viscosity mainly) are crucial with a view to producing efficient lubricants for specific applications. Usually, POE formulations, which usually contain several bases, are characterized in terms of global indices. In this ... Talanta journals http://www.medworm.com/rss/comments.php?id=5656788 Mon, 30 Jan 2012 05:00:00 +0100 5656788 http://www.medworm.com/index.php?rid=5656787&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284521%26dopt%3DAbstract This study extends the approach to a much larger, statistically meaningful sixty bottle wine library where bivariate statistics are used to comment on the measured data. The full bottle diamagnetic screening of thirty-six identically labeled, sealed bottles of wine obtained from four different sources combined with principal component analysis data reduction followed by treatment with a bivariate distribution permit the effect of wine transport and storage to be observed. The usefulness and future success of the method towards the identification of counterfeit wines is mentioned. PMID: 22284521 [PubMed - in process] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=5656787 Mon, 30 Jan 2012 05:00:00 +0100 5656787 http://www.medworm.com/index.php?rid=5656786&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284522%26dopt%3DAbstract This study describes a new approach for the investigation of electrocatalytic oxidation of sulfide using a pencil graphite electrode modified with quercetin (PGE/QH(2)). Adsorption procedure was used for the preparation of the modified electrodes. It was observed that PGE/QH(2) showed a significant electrocatalytic activity toward sulfide oxidation. Cyclic voltammetric studies show that the peak potential of sulfide shifts from +450mV at bare PGE to +280mV at PGE/QH(2). The electrocatalytic currents obtained from amperometric measurements at +300mV vs. Ag/AgCl/KCl(sat) and at pH 8.0 BR buffer solution containing 0.1M NH(4)Cl were linearly related to the concentration of sulfide. The calibration graph consisted of two linear segments of 1-20μM and 20-800μM with a detection limit of 0.3μM... Talanta journals http://www.medworm.com/rss/comments.php?id=5656786 Mon, 30 Jan 2012 05:00:00 +0100 5656786 http://www.medworm.com/index.php?rid=5656785&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284523%26dopt%3DAbstract Authors: Laglera LM, Tovar-Sánchez A Abstract Thiols and thioamides form part of the pool of reduced sulfur substances (RSS) that modify the health of aquatic ecosystems acting as radical scavengers and heavy metal ligands. Their concentrations could be easily determined in seawater by cathodic stripping voltammetry (CSV) were it not be for the coalescence of their responses in a single peak. Here, we modified the traditional CSV method of RSS analysis to allow individual recognition and quantification in thiol/thioamide mixes. Glutathione, cysteine, thiourea and thioacetamide in UV digested seawater were repeatedly analyzed shifting the deposition potential (E(dep)) in the range +0.07 to -0.4V at high resolution. The representation of peak height (i(p)) and peak potential (E(p)) ... Talanta journals http://www.medworm.com/rss/comments.php?id=5656785 Mon, 30 Jan 2012 05:00:00 +0100 5656785 http://www.medworm.com/index.php?rid=5656784&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284524%26dopt%3DAbstract Authors: Chen FF, Wang R, Shi YP Abstract Molecular imprinted polymers (MIPs) were prepared by thermal polymerization using a non-covalent molecularly imprinting strategy with kirenol as the template, acrylamide (AM) as the functional monomer and ethylene glycol dimethacrylamide (EGDMA) as the cross-linker in the porogen of tetrahydrofuran (THF). The synthesized MIPs were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). Its molecular recognition property was investigated by UV spectrogram. High-pressure liquid chromatography (HPLC) was used for analysis of target analytes. The polymers were evaluated further by batch rebinding experiments, and from the derived isotherms their binding capacity and binding strength were determined. Then the ... Talanta journals http://www.medworm.com/rss/comments.php?id=5656784 Mon, 30 Jan 2012 05:00:00 +0100 5656784 http://www.medworm.com/index.php?rid=5656783&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284525%26dopt%3DAbstract Authors: Gholivand MB, Karimian N, Malekzadeh G Abstract Using a molecularly imprinted polymer (MIP) as a recognition element, the design and construction of a high selective voltammetric sensor for propazine were introduced. A computational approach was developed to study the intermolecular interactions in the pre-polymerization mixture and to find a suitable functional monomer in MIP preparation. Having confirmed the results of computational method, three MIPs were synthesized with functional monomers methacrylic acid (MAA), acrylamide (AAM) and 4-vinylpyridine (4-VP). The results indicated that to prepare MIPs, acrylamide (AAM) is the best candidate. A propazine selective MIP and a nonimprinted polymer (NIP) were synthesized and then incorporated in the carbon paste electrodes (... Talanta journals http://www.medworm.com/rss/comments.php?id=5656783 Mon, 30 Jan 2012 05:00:00 +0100 5656783 http://www.medworm.com/index.php?rid=5656782&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284526%26dopt%3DAbstract Authors: Rodrigues C, Portugal FC, Nogueira JM Abstract Static headspace sorptive extraction using polyurethane foams (HSSE(PU)) followed by gas chromatography coupled to mass spectrometry is proposed for volatile analysis. The application of this novel analytical approach to characterize the volatiles profile from roasted coffee samples, selected as model system, revealed remarkable advantages under convenient experimental conditions. The comparison of HSSE(PU) with other well-established procedures, such as headspace sorptive extraction using polydimethylsiloxane (HSSE(PDMS)) and headspace solid phase microextraction using carboxen/polydimethylsiloxane fibers (HS-SPME(CAR/PDMS)), showed that the former presented much higher capacity, sensitivity and even selectivity, where larger... Talanta journals http://www.medworm.com/rss/comments.php?id=5656782 Mon, 30 Jan 2012 05:00:00 +0100 5656782 http://www.medworm.com/index.php?rid=5656781&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284527%26dopt%3DAbstract In this study an automatic method for sample treatment and spectrophotometric determination of hydroxyproline in commercial sausages was developed. A flow-batch system that includes the steps of sample hydrolysis and determination of the analyte was designed. The method presents a linear range between 0.60 and 3.60μgmL(-1) of hydroxyproline. A relative standard deviation of 1.68% was obtained from hydroxyproline standard solution (n=6, 1.20μgmL(-1)) and the detection limit was 0.12μgmL(-1). The sample throughput was 1sampleh(-1) while the reference method (AOAC) was carried out in about 17h. This method employs 16h of hydrolysis while in the proposed method the hydrolysis time was 15min. For this purpose a pressure hydrolysis chamber with a low cost halogen lamp was used. The flow-batch... Talanta journals http://www.medworm.com/rss/comments.php?id=5656781 Mon, 30 Jan 2012 05:00:00 +0100 5656781 http://www.medworm.com/index.php?rid=5656780&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22284528%26dopt%3DAbstract Authors: Jin Y, Huang Y, Xie Y, Hu W, Wang F, Liu G, Zhao R Abstract The cyclic oxidation and reduction of methionine (Met) containing peptides and proteins play important roles in biological system. This work was contributed to analysis the cyclic oxidation and reduction processes of a methionine containing peptide which is very likely to relate in the cell signal transduction pathways. To mimic the biological oxidation condition, hydrogen peroxide was used as the reactive oxygen species to oxidize the peptide. Reversed-phase high-performance liquid chromatography and mass spectrometry were employed to monitor the reactions and characterize the structural changes of the products. A rapid reduction procedure was developed by simply using KI as the reductant, which is green and high... Talanta journals http://www.medworm.com/rss/comments.php?id=5656780 Mon, 30 Jan 2012 05:00:00 +0100 5656780 http://www.medworm.com/index.php?rid=5637700&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fsites%2Fentrez%3Fcmd%3DSearch%26db%3Dpubmed%26term%3D%28%2520%28%2522Talanta%2522%255Bta%255D%29%2520AND%2520%25222011%252F11%252F23%252009.36%2522%255BEDAT%255D%253A%25222012%252F01%252F28%252022.12%2522%255BEDAT%255D%29 110 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results: "Talanta"[ta] These pubmed results were generated on 2012/01/28PubMed, a service of the National Library of Medicine, includes over 15 million citations for biomedical articles back to the 1950's. These citations are from MEDLINE and additional life science journals. PubMed includes links to many sites providing full text articles and other related resources. (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=5637700 Sun, 29 Jan 2012 03:12:01 +0100 5637700 http://www.medworm.com/index.php?rid=5437820&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099640%26dopt%3DAbstract Authors: Spietelun A, Pilarczyk M, Kloskowski A, Namieśnik J Abstract The article discusses the merits and limitations of commercially available solid-phase microextraction (SPME) fibres and compares them with the new type of extraction coatings, in particular those containing polyethylene glycol as sorbent, as well as the methods of the preparation of the latter. It also analyses their possible application for the extraction of a broad spectrum of analytes, with particular emphasis on the sampling of polar organic compounds from different media. PMID: 22099640 [PubMed - in process] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=5437820 Wed, 23 Nov 2011 14:43:14 +0100 5437820 http://www.medworm.com/index.php?rid=5437819&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099641%26dopt%3DAbstract Authors: Guérin N, Nadeau K, Larivière D Abstract This paper describes a novel strategy for actinide separation by extraction chromatography with Np(III) valence adjustment. Neptunium(IV) was reduced to Np(III) using Cr(II) and then selectively separated from uranium (IV) on a TEVA resin. After elution, Np(III) was retained on a DGA resin in order to remove any detrimental chromium impurities. Neptunium(III) formation was demonstrated by the complete and selective elution of Np from TEVA resin (99±7%) in less than 12mL of 9M HCl from U(IV) (0.7±0.7%). It was determined by UV-visible and kinetic studies that Cr(II) was the only species responsible for the elution of Np(IV) as Np(III) and that the Cr(II) solution could be prepared from 2 to 30min before its use without the need o... Talanta journals http://www.medworm.com/rss/comments.php?id=5437819 Wed, 23 Nov 2011 14:43:05 +0100 5437819 http://www.medworm.com/index.php?rid=5437818&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099642%26dopt%3DAbstract Authors: Periasamy AP, Yang S, Chen SM Abstract In this work, preparation and characterization of a novel nanocomposite containing bismuth oxide (Bi(2)O(3)) nanoparticles and multiwalled carbon nanotubes (MWCNTs) was presented. Powder X-ray diffraction (XRD) studies revealed that as-synthesized Bi(2)O(3) nanoparticles are crystalline and belong to α-phase with monoclinic symmetry. Field emission scanning electron microscopy (FESEM) study results showed that the size of Bi(2)O(3) nanoparticles is 50nm. Energy-dispersive X-ray (EDX) spectra of as-prepared Bi(2)O(3)-MWCNT nanocomposite displayed characteristic Bi and C peaks which confirmed the incorporation of Bi(2)O(3) with MWCNT. The prepared Bi(2)O(3)-MWCNT was also characterized by scanning electron microscopy (SEM) and atomic f... Talanta journals http://www.medworm.com/rss/comments.php?id=5437818 Wed, 23 Nov 2011 14:42:57 +0100 5437818 http://www.medworm.com/index.php?rid=5437817&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099643%26dopt%3DAbstract Authors: Takasaki Y, Inagaki K, Sabarudin A, Fujii S, Iwahata D, Takatsu A, Chiba K, Umemura T Abstract A method for multielement analysis of micro-volume biological sample by inductively coupled plasma mass spectrometry (ICP-MS) with a highly efficient sample introduction system was presented. The sample introduction system was the combination of (1) an inert loop injection unit and (2) a high performance concentric nebulizer (HPCN) coupled with a temperature controllable cyclone chamber. The loop injection unit could introduce 20μL samples into the carrier liquid flow of 10μLmin(-1) producing a stable signal for 100s without any dilution. The injection loop is continuously washed with 0.1M HNO(3) carrier solution during the measurement, thereby much improving sample throughput.... Talanta journals http://www.medworm.com/rss/comments.php?id=5437817 Wed, 23 Nov 2011 14:42:48 +0100 5437817 http://www.medworm.com/index.php?rid=5437816&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099644%26dopt%3DAbstract Authors: Fernandes DD, Gomes AA, Costa GB, Silva GW, Véras G Abstract This work is concerned of evaluate the use of visible and near-infrared (NIR) range, separately and combined, to determine the biodiesel content in biodiesel/diesel blends using Multiple Linear Regression (MLR) and variable selection by Successive Projections Algorithm (SPA). Full spectrum models employing Partial Least Squares (PLS) and variables selection by Stepwise (SW) regression coupled with Multiple Linear Regression (MLR) and PLS models also with variable selection by Jack-Knife (Jk) were compared the proposed methodology. Several preprocessing were evaluated, being chosen derivative Savitzky-Golay with second-order polynomial and 17-point window for NIR and visible-NIR range, with offset correction. A t... Talanta journals http://www.medworm.com/rss/comments.php?id=5437816 Wed, 23 Nov 2011 14:42:40 +0100 5437816 http://www.medworm.com/index.php?rid=5437815&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099645%26dopt%3DAbstract Authors: Wang J, Cai Q, Fang Y, Anderson TA, Cobb GP Abstract In this new century, nanotechnology has evolved from a novel concept to an integral aspect of product advancement. With an increasing presence of nanomaterials in commercial products, more concern about the impact of nanomaterials on human health and also the environment has been considered and evaluated. Fullerenes (C60), have been studied in several different areas and applied widely. Wider application of fullerenes into different products in the recent decades has increased the potential of fullerene releases into the environment. Fullerene research involves physical and chemical characteristics, toxicity, environment fate, and interaction with other pollutions. However, few studies have addressed fullerene quantifica... Talanta journals http://www.medworm.com/rss/comments.php?id=5437815 Wed, 23 Nov 2011 14:42:32 +0100 5437815 http://www.medworm.com/index.php?rid=5437814&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099646%26dopt%3DAbstract Authors: Khaled E, El-Sabbagh IA, El-Kholy NG, Ghahni EY Abstract The construction and performance characteristics of Biperiden (BP) polyvinyl chloride (PVC) electrodes are described. Different methods for electrode fabrication are tested including; incorporation of BP-ion pairs (BP-IPs), incorporation of ion pairing agents, or soaking the plain electrode in BP-ion pairs suspension solution. Electrode matrices were optimized referring to the effect of modifier content and nature, plasticizer and the method of modification. The proposed electrodes work satisfactorily in the BP concentration range from 10(-5) to 10(-2)molL(-1), with fast response time (7s) and adequate operational lifetime (28 days). The electrode potential is pH independent within the range 2.0-7.0, with good select... Talanta journals http://www.medworm.com/rss/comments.php?id=5437814 Wed, 23 Nov 2011 14:42:23 +0100 5437814 http://www.medworm.com/index.php?rid=5437813&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099647%26dopt%3DAbstract Authors: Lavine BK, Mirjankar N, Ryland S, Sandercock M Abstract Currently, the identification of the make, model and year of a motor vehicle involved in a hit and run collision from only a clear coat paint smear left at a crime scene is not possible. Search prefilters for searching infrared (IR) spectral libraries of the paint data query (PDQ) automotive database to differentiate between similar but nonidentical Fourier transform infrared (FTIR) paint spectra are proposed. Applying wavelets, FTIR spectra of clear coat paint smears can be denoised and deconvolved by decomposing each spectrum into wavelet coefficients which represent the sample's constituent frequencies. A genetic algorithm for pattern recognition analysis is used to identify wavelet coefficients for underdetermined... Talanta journals http://www.medworm.com/rss/comments.php?id=5437813 Wed, 23 Nov 2011 14:42:15 +0100 5437813 http://www.medworm.com/index.php?rid=5437812&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099648%26dopt%3DAbstract We report the effectiveness of laser-induced breakdown spectroscopy (LIBS) in probing the content of pharmaceutical tablets and also investigate its feasibility for routine classification. This method is particularly beneficial in applications where its exquisite chemical specificity and suitability for remote and on site characterization significantly improves the speed and accuracy of quality control and assurance process. Our experiments reveal that in addition to the presence of carbon, hydrogen, nitrogen and oxygen, which can be primarily attributed to the active pharmaceutical ingredients, specific inorganic atoms were also present in all the tablets. Initial attempts at classification by a ratiometric approach using oxygen (∼777nm) to nitrogen (742.36nm, 744.23nm and 746.83nm) com... Talanta journals http://www.medworm.com/rss/comments.php?id=5437812 Wed, 23 Nov 2011 14:42:06 +0100 5437812 http://www.medworm.com/index.php?rid=5437811&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099649%26dopt%3DAbstract Authors: Ortiz González I, Pérez Pastor RM, Sánchez Hervás JM Abstract The uncertainty evaluation associated with the quantification of tar from gasification of sewage sludge is present. Each of the sources of uncertainty associated with the wet type sampling method and GC-MS analysis was identified to determine the critical stages of the analytical methodology in order to reduce them. The study shows that major contributions to the overall uncertainty are related to extraction steps. High expanded uncertainties were found for all compounds, due to the segregation of the tar in different samples because of the sampling method. However, the analytical method used was successfully applied for the evaluation of the tar cleaning filter in a real gasification plant. PMID: 220996... Talanta journals http://www.medworm.com/rss/comments.php?id=5437811 Wed, 23 Nov 2011 14:41:58 +0100 5437811 http://www.medworm.com/index.php?rid=5437810&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099650%26dopt%3DAbstract Authors: Damar K, Odaci Demirkol D Abstract An electrochemical biosensor for detection of fructose in food samples was developed by immobilization of fructose dehydrogenase (FDH) on cysteamine and poly(amidoamine) dendrimers (PAMAM)-modified gold electrode surface. Electrochemical analysis was carried out by using hexacyanoferrate (HCF) as a mediator and the response time was 35s at +300mV vs. Ag/AgCl. Moreover, some parameters such as pH, enzyme loading and type of PAMAM (Generations 2, 3 and 4) were investigated. Then, the FDH biosensor was calibrated for fructose in the concentration range of 0.25-5.0mM. To evaluate its utility, the FDH biosensor was applied for fructose analysis in real samples. Finally, obtained data were compared with those measured with HPLC as a reference m... Talanta journals http://www.medworm.com/rss/comments.php?id=5437810 Wed, 23 Nov 2011 14:41:49 +0100 5437810 http://www.medworm.com/index.php?rid=5437809&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099651%26dopt%3DAbstract In this study, the phenylboronic acid esters of fructose, galactose, glucose and raffinose were synthesized and then used as template analytes. The adsorption capacities of fructose, galactose and glucose-phenylboronic acid imprinted polymers were 75, 10 and 30%, respectively. The batch rebinding studies and Scatchard analysis were done for all sugar imprinted polymer. Glucose is one of the mostly found sugar in the urine. The glucose:phenylboronic acid imprinted polymer was used for the analysis of glucose, fructose, galactose, sucrose, maltose, lactose and raffinose in spiked urine. The selectivity of glucose:phenylboronic acid imprinted polymer to urine monosaccharides was found as nearly 45-55% and to di- and polysaccharides was found as 30-35%, respectively. PMID: 22099651 [PubMed... Talanta journals http://www.medworm.com/rss/comments.php?id=5437809 Wed, 23 Nov 2011 14:41:40 +0100 5437809 http://www.medworm.com/index.php?rid=5437808&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099652%26dopt%3DAbstract Authors: Kalaiselvan S, Lakshmanan AR, Meenakshisundaram V Abstract A relatively less expensive and less time consuming radio analytical technique for quantitative determination of Th(nat) in urine at mBq level is developed and reported in this paper. Th in urine is co-precipitated with Ca(3)(PO(4))(2) from wet oxidized urine matrix and the precipitate is dissolved in HNO(3) and evaporated to dryness. The residue is dissolved in 3M HCl and 200mg of Na-EDTA is added to mask Ca(2+), Mg(2+) and Fe(3+) ions. Th(4+) is extracted into 0.01M PC-88A (2-ethyl hexyl phosphonic acid mono-2-ethylhexyl ester), dissolved in toluene from the experimentally optimized pH 2.5±0.3 in aqueous phase. Th(4+) is stripped into 8.0M HCl and evaporated to dryness. The content of the beaker is dissolved in ... Talanta journals http://www.medworm.com/rss/comments.php?id=5437808 Wed, 23 Nov 2011 14:41:31 +0100 5437808 http://www.medworm.com/index.php?rid=5437807&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099653%26dopt%3DAbstract Authors: Superville PJ, Louis Y, Billon G, Prygiel J, Omanović D, Pižeta I Abstract An adaptable automatic trace metal monitoring system (ATMS) was assembled and embedded in a mobile monitoring station belonging to the French Water Agency Artois-Picardie (AEAP) and deployed in the field to measure the concentration of trace metals (electroactive and acid leachable fractions) in natural waters by anodic stripping voltammetry with a hanging mercury drop electrode. Cathodic stripping voltammetry procedures were included to estimate the concentration of dissolved oxygen and reduced sulphur species. The concept of the measuring system enables easy adaptation of methods and procedures to analytes of concern and gives the opportunity to undertake in real-time a routine analysis of the d... Talanta journals http://www.medworm.com/rss/comments.php?id=5437807 Wed, 23 Nov 2011 14:41:22 +0100 5437807 http://www.medworm.com/index.php?rid=5437797&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099654%26dopt%3DAbstract Authors: Li H, Guo J, Ping H, Liu L, Zhang M, Guan F, Sun C, Zhang Q Abstract With citrate-coated Au nanoparticles as colorimetric probe, a novel visual method for rapid assay of organophosphorus pesticides has been developed. The assay principle is based on catalytic hydrolysis of acetylthiocholine into thiocholine by acetylcholinesterase, which induces the aggregation of Au nanoparticles and the color change from claret-red to purple or even grey. The original plasmon absorption of Au nanoparticles at 522nm decreases, and simultaneously, a new absorption band appears at 675nm. The irreversible inhibition of organophosphorus pesticides on acetylcholinesterase prevents aggregation of Au nanoparticles. Under optimum conditions, the absorbance at 522nm of Au nanoparticles is related ... Talanta journals http://www.medworm.com/rss/comments.php?id=5437797 Wed, 23 Nov 2011 14:41:13 +0100 5437797 http://www.medworm.com/index.php?rid=5437796&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099655%26dopt%3DAbstract Authors: Zhang N, Xiao F, Bai J, Lai Y, Hou J, Xian Y, Jin L Abstract A novel label-free electrochemical immunosensor for rapid determination of chloramphenicol (CAP) was fabricated by entrapping monoclonal antibody to chloramphenicol (anti-CAP) in hollow gold nanospheres (HGNs)/chitosan composite modified on a glassy carbon electrode. The hollow gold nanospheres (HGNs) were prepared by using Co nanoparticles as sacrificial templates and characterized by transmission electron microscopy (TEM). The changes of the electrode behavior after each fabrication step were investigated by electrochemical impedance spectroscopy (EIS) technique. Under optimal conditions, the proposed immunosensor has a sensitive response to CAP in a linear range of 0.1-1000ngmL(-1) with the detection limit of ... Talanta journals http://www.medworm.com/rss/comments.php?id=5437796 Wed, 23 Nov 2011 14:41:03 +0100 5437796 http://www.medworm.com/index.php?rid=5437795&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099656%26dopt%3DAbstract Authors: Sun W, Qi X, Chen Y, Liu S, Gao H Abstract In this paper a Fe(3)O(4) microsphere, graphene (GR) and chitosan (CTS) nanocomposite material modified carbon ionic liquid electrode (CILE) was used as the platform for the construction of a new electrochemical DNA biosensor. The single-stranded DNA (ssDNA) probe was immobilized directly on the surface of the CTS/Fe(3)O(4)-GR/CILE, which could hybridize with the target ssDNA sequence at the selected conditions. By using methylene blue (MB) as the electrochemical indicator the hybridization reaction was investigated with the reduction peak current measured. By combining the specific properties such as the biocompatibility and big surface area of Fe(3)O(4) microspheres, the excellent electron transfer ability of GR, the good film-f... Talanta journals http://www.medworm.com/rss/comments.php?id=5437795 Wed, 23 Nov 2011 14:40:54 +0100 5437795 http://www.medworm.com/index.php?rid=5437794&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099657%26dopt%3DAbstract Authors: Ponhong K, Teshima N, Grudpan K, Motomizu S, Sakai T Abstract A novel simultaneous injection effective mixing analysis system (SIEMA) for determination of direct bilirubin in urine sample was developed. Bilirubin reacts with diazotized sulfanilic acid in the presence of n-octyl-β-d-thioglucoside (OTG) as a solubilizing agent to form OTG-azobilirubin. The flow and chemical variables were investigated. A linear calibration graph for direct bilirubin was obtained over the range of 0-1.0mgL(-1) (r(2)=0.994) with the limit of detection (3σ) of 4.7μgL(-1), and the relative standard deviation (RSD) being 1.9% (n=11, 0.5mgL(-1) of direct bilirubin). The results in healthy adult urine obtained by the proposed approach were found in good agreement with those obtained by the batch... Talanta journals http://www.medworm.com/rss/comments.php?id=5437794 Wed, 23 Nov 2011 14:40:44 +0100 5437794 http://www.medworm.com/index.php?rid=5437793&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099658%26dopt%3DAbstract The objective is optimization of extraction conditions, GC adjustments and data processing. Experiments were conducted on the real sample of Iranian offshore crude oil by a carboxen/PDMS fiber via a GC equipped with a cross-linked polyethylene glycol column and FID. The results revealed that this fiber adsorbed the alcohols among other light non-polar compounds of crude oil. Moreover, the interference effects of ethanol were solved by proper selection of thermal program. The LOD, LOQ and linear range of this approach were determined to be 3.9, 12.9 and 14-229mgL(-1) for methanol, respectively. Moreover, the sensitivity was 30 area-counts per mgL(-1). Using the standard calibration and the standard addition methods, the relative errors of 1.6-7.2 and 5.3-14.0% were determined, respectively.... Talanta journals http://www.medworm.com/rss/comments.php?id=5437793 Wed, 23 Nov 2011 14:40:34 +0100 5437793 http://www.medworm.com/index.php?rid=5437781&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099659%26dopt%3DAbstract Authors: Betelu S, Polychronopoulou K, Rebholz C, Ignatiadis I Abstract Nuclear waste repositories are being installed in deep excavated rock formations in some places in Europe to isolate and store radioactive waste. In France, the Callovo-Oxfordian formation (COx) is a possible candidate for nuclear waste storage. This work investigates the applicability of CeO(2)-based oxides (CeO(2), Ce(0.8)Sm(0.2)O(2) and Ce(0.8)Zr(0.2)O(2)) for monitoring the pH of the COx pore water (T=25°C). The study is limited to the pH range between 5.5 and 13.2, which includes the pH values that have been encountered or are anticipated in the COx formation during its evolution as radioactive waste repository due mainly to alkalinisation, an increase in salinity, and a decrease in redox potential. Scree... Talanta journals http://www.medworm.com/rss/comments.php?id=5437781 Wed, 23 Nov 2011 14:40:25 +0100 5437781 http://www.medworm.com/index.php?rid=5437780&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099660%26dopt%3DAbstract Authors: Vera L, Aceña L, Guasch J, Boqué R, Mestres M, Busto O Abstract Beer samples of the same brand and commercialized as a same product, but brewed in four different factories were analyzed with three techniques, an MS e-nose, a mid-IR optical-tongue and a UV-visible, to see if the factories show differences and to find out if the differences found could be attributed to different sensory properties. The data from the three instruments were fused to improve the ability of classification with respect to the individual use of the techniques. Two levels of data fusion were studied: low and mid level fusion, and the classification was performed by linear discriminant analysis (LDA). Mid-level fusion provided better classification results (above 95% correct classification) than t... Talanta journals http://www.medworm.com/rss/comments.php?id=5437780 Wed, 23 Nov 2011 14:40:15 +0100 5437780 http://www.medworm.com/index.php?rid=5437779&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099661%26dopt%3DAbstract Authors: Onwudili JA, Hajizadeh Y, Zainal S, Upton J, Williams PT Abstract The seventeen 2378-substituted polychlorinated dibenzo-p-dioxins and dibenzo-p-furans (PCDD/Fs) congeners have been separated and analyzed in sewage sludge and incinerator flyash samples using a CP-Sil 88 column (50m×0.25mm I.D., 0.25μm film thickness) operating at a maximum oven temperature of 240°C. The column was used on a Varian 450-GC with a Varian 320-MS Triple Quadrupole. Calibration standards were used to determine the transition chemistries of the 2378-substituted PCDD/F congeners in the gas chromatography/mass spectrometry (GC-MS/MS) system. The five-point calibration curve for each of the congeners showed very good linearity with R(2) values greater than 0.999. The recovery of labelled compound... Talanta journals http://www.medworm.com/rss/comments.php?id=5437779 Wed, 23 Nov 2011 14:40:05 +0100 5437779 http://www.medworm.com/index.php?rid=5437778&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099662%26dopt%3DAbstract Authors: Tölgyessy P, Vrana B, Krascsenits Z Abstract The development of a method for screening of organic compounds with a wide range of physico-chemical properties in water, based on dual stir bar sorptive extraction coupled with thermal desorption and gas chromatography-mass spectrometry (dual SBSE-TD-GC-MS) is described. The investigated water sample is divided into two aliquots and extracted with stir bar sorptive extraction at two different conditions: using addition of methanol or sodium chloride, respectively. Following extraction, the two stir bars are inserted into the same glass thermal desorption liner and are simultaneously desorbed and analysed by GC-MS. The method optimisation was performed using 45 environmentally harmful substances with different volatilities (boi... Talanta journals http://www.medworm.com/rss/comments.php?id=5437778 Wed, 23 Nov 2011 14:39:55 +0100 5437778 http://www.medworm.com/index.php?rid=5437777&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099663%26dopt%3DAbstract Authors: Jońca J, León Fernández V, Thouron D, Paulmier A, Graco M, Garçon V Abstract Initial steps to create an autonomous in situ electrochemical sensor for orthophosphate determination in seawater are presented. First, the optimal conditions to form the molybdophosphate complex in artificial seawater medium were determined by addition of sulphuric acid and sodium molybdate to the solution containing orthophosphate. Secondly, the anodic oxidation of molybdenum to form molybdate ions and protons was used to create the molybdophosphate complex without addition of any liquid reagents. The molybdophosphate complex is detectable by amperometry with an average precision of 2.2% for the concentration range found in the open ocean and the detection limit is 0.12μM. Three solutions a... Talanta journals http://www.medworm.com/rss/comments.php?id=5437777 Wed, 23 Nov 2011 14:39:46 +0100 5437777 http://www.medworm.com/index.php?rid=5437776&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099664%26dopt%3DAbstract Authors: Mehyou Z, Lobinski R, Hagège A Abstract A simple protocol to obtain Cu(II)-IDA (iminodiacetic acid)-modified capillaries was developed for immobilized metal ion affinity chromatography (IMAC). It consisted in the synthesis of IDA-silane used for a one-step coating of fused silica capillaries. The approach prevented the hydrolysis of silica potentially induced by two step coatings (γ-GPTMS, then IDA) employed in the conventional method of bonding iminodiacetic acid. The IDA content was quantified using a model relating the electroosmotic flow generated in IDA-modified capillaries to the charges induced by IDA species. The retention behavior of holotransferrin and bovine serum albumin on these IMAC columns was then investigated. Holotransferrin revealed a high affinity for... Talanta journals http://www.medworm.com/rss/comments.php?id=5437776 Wed, 23 Nov 2011 14:39:36 +0100 5437776 http://www.medworm.com/index.php?rid=5437775&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099665%26dopt%3DAbstract Authors: Gros N Abstract A novel setup is described in which we combined the separation of a volatile substance from a sample with a complex matrix on the basis of a microdiffusion process with a kinetic on-line spectrometric monitoring of the reaction in the receptive medium at 365nm. The fruit juice was selected as a model for testing the performance of the setup in real-life applications. The ethanol content in fruit juice can be considered as an indicator of the fruit-juice quality and should not exceed the regulatory limiting values. After optimising the microdiffusion process, blackcurrant, orange and two varieties of apple juice were analysed. The sample analysis lasted 15min at 35°C. The ethanol concentrations were found to be between 0.9 and 4.0mmol/L, and were comparable... Talanta journals http://www.medworm.com/rss/comments.php?id=5437775 Wed, 23 Nov 2011 14:39:25 +0100 5437775 http://www.medworm.com/index.php?rid=5437774&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099666%26dopt%3DAbstract Authors: Lavagnini I, Badocco D, Pastore P, Magno F Abstract This paper reports the combined use of the nonparametric Theil-Sen (TS) regression technique and of the statistics of Lancaster-Quade (LQ) concerning the linear regression parameters to solve typical analytical problems, like method comparison, calculation of the uncertainty in the inverse regression, determination of the detection limit. The results of this new approach are compared to those obtained with appropriate reference methods, using simulated and real data sets. The nonparametric Theil-Sen regression technique appears a new robust tool for the problems considered because it is free from restrictive statistical constraints, avoids searching for the error nature on x and y, which may require long analysis times, a... Talanta journals http://www.medworm.com/rss/comments.php?id=5437774 Wed, 23 Nov 2011 14:39:16 +0100 5437774 http://www.medworm.com/index.php?rid=5437773&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099667%26dopt%3DAbstract In this study, new xanthine biosensors, XO/Au/PVF/Pt and XO/Pt/PVF/Pt, based on electroless deposition of gold(Au) and platinum(Pt) nanoparticles on polyvinylferrocene(PVF) coated Pt electrode for detection of xanthine were presented. The amperometric responses of the enzyme electrodes were measured at the constant potential, which was due to the electrooxidation of enzymatically produced H(2)O(2). Compared with XO/PVF/Pt electrode, XO/Au/PVF/Pt and XO/Pt/PVF/Pt exhibited excellent electrocatalytic activity towards the oxidation of the analyte. Effect of Au and Pt nanoparticles was investigated by monitoring the response currents at the different deposition times and the different concentrations of KAuCl(4) and PtBr(2). Under the optimal conditions, the calibration curves of XO/Au/PVF/Pt a... Talanta journals http://www.medworm.com/rss/comments.php?id=5437773 Wed, 23 Nov 2011 14:39:05 +0100 5437773 http://www.medworm.com/index.php?rid=5437772&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099668%26dopt%3DAbstract Authors: Quelle C, Besada V, Andrade JM, Gutiérrez N, Schultze F, Gago J, González JJ Abstract A suite of relevant trace metals (Hg, Pb, Cd, Cu, Zn and Ni) was measured in surface sediment samples to assess the environmental situation of the largest two Atlantic Spanish 'rías' (a form of estuaries, ría of Pontevedra, ROP, and ría of Vigo, ROV). The level of contamination originated by these metals was assessed against international guidelines, the threshold effect, ERL, and the midrange effect, ERM. Six unsupervised and supervised multivariate chemometric techniques were applied to model each ría, compare them and select those metals that characterize the samples. This is first time that such a study is performed for these two important seafood-producing areas. Maximum concen... Talanta journals http://www.medworm.com/rss/comments.php?id=5437772 Wed, 23 Nov 2011 14:38:55 +0100 5437772 http://www.medworm.com/index.php?rid=5437771&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099669%26dopt%3DAbstract Authors: Bueno L, Paixão TR Abstract A new approach for the discrimination of the adulteration process of ethanol fuel with water is reported using a copper interdigitated electrode and chemometrical tools. The sensor was constructed using copper sheets with non-chemical modification of the electrode surface. The discrimination process was performed using capacitance values recorded at different frequencies (1000Hz to 0.1MHz) as the input data for non-supervised pattern recognition methods (PCA: principal component analysis and HCA: hierarchical cluster analysis). The relative standard deviation for the capacitance signals obtained from ten independent interdigitated sensors was below 5.0%. The ability of the device to differentiate non-adulterated ethanol samples from those adult... Talanta journals http://www.medworm.com/rss/comments.php?id=5437771 Wed, 23 Nov 2011 14:38:46 +0100 5437771 http://www.medworm.com/index.php?rid=5437767&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099670%26dopt%3DAbstract In this study, a lysosome specific probe W-7 was designed and synthesized via convenient one-pot reaction and Heck reaction. This probe was derived from Tröger's base with a dimethylaminomethyl end group. The optical properties of this compound were measured. W-7 also showed two-photon absorption (TPA) effect by using laser excitation at the wavelength of infrared light. In vivo experiment, W-7 showed high specificity and selectivity for lysosomes in living cells (HeLa cells, MRC-5 cells and NRK cells), compared with LT Red, GT Red and MT Red (R=0.96). Two-photon fluorescence images of HeLa cells stained by W-7 were obtained. And high resolution 3D reconstruction of lysosomes in one HeLa cell was provided by using two-photon confocal microscopy. The anantioseparation of racemic W-7 was ca... Talanta journals http://www.medworm.com/rss/comments.php?id=5437767 Wed, 23 Nov 2011 14:38:37 +0100 5437767 http://www.medworm.com/index.php?rid=5437766&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099671%26dopt%3DAbstract Authors: Elkady EF, Fouad MA Abstract A simple, selective and precise stability-indicating reversed-phase liquid chromatographic method was developed and validated for the determination of ciclesonide. Ciclesonide was subjected to acid and alkali hydrolysis, oxidation, thermal and photo-degradation. The degradation products were well separated from the pure drug. The method was based on isocratic elution of ciclesonide and its degradation products on reversed phase C18 column (250mm×4.6mm, 10μm) - Phenomenex using a mobile phase consisting of ethanol-water (70:30, v/v) at a flow rate of 1mLmin(-1). Quantitation was achieved with UV detection at 242nm. Linearity, accuracy and precision were found to be acceptable over the concentration range of 5-200μgmL(-1). Desisobutyryl-cicles... Talanta journals http://www.medworm.com/rss/comments.php?id=5437766 Wed, 23 Nov 2011 14:38:29 +0100 5437766 http://www.medworm.com/index.php?rid=5437764&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099672%26dopt%3DAbstract Authors: Isa IM, Mustafar S, Ahmad M, Hashim N, Ghani SA Abstract A new cobalt(II) ion selective electrode based on palladium(II) dichloro acetylthiophene fenchone azine(I) has been developed. The best membrane composition is found to be 10:60:10:21.1 (I)/PVC/NaTPB/DOP (w/w). The electrode exhibits a Nerstian response in the range of 1.0×10(-1)-1.0×10(-6)M with a detection limit and slope of 8.0×10(-7)M and 29.6±0.2mV per decade respectively. The response time is within the range of 20-25s and can be used for a period of up to 4 months. The electrode developed reveals good selectivity for cobalt(II) and could be used in pH range of 3-7. The electrode has been successfully used in the determination of cobalt(II) in water samples. PMID: 22099672 [PubMed - in process] (Source:... Talanta journals http://www.medworm.com/rss/comments.php?id=5437764 Wed, 23 Nov 2011 14:38:20 +0100 5437764 http://www.medworm.com/index.php?rid=5437763&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099673%26dopt%3DAbstract Authors: Sartori ER, Vicentini FC, Fatibello-Filho O Abstract The modification of a glassy carbon electrode with multi-walled carbon nanotubes and gold nanoparticles within a poly(allylamine hydrochloride) film for the development of a biosensor is proposed. This approach provides an efficient method used to immobilize polyphenol oxidase (PPO) obtained from the crude extract of sweet potato (Ipomoea batatas (L.) Lam.). The principle of the analytical method is based on the inhibitory effect of sulfite on the activity of PPO, in the reduction reaction of o-quinone to catechol and/or the reaction of o-quinone with sulfite. Under the optimum experimental conditions using the differential pulse voltammetry technique, the analytical curve obtained was linear in the concentration of sulf... Talanta journals http://www.medworm.com/rss/comments.php?id=5437763 Wed, 23 Nov 2011 14:38:12 +0100 5437763 http://www.medworm.com/index.php?rid=5437762&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099674%26dopt%3DAbstract Authors: Liu X, Zhu H, Yang X Abstract In this article, poly(diallydimethylammonium chloride) (PDDA) functionalized graphene-Fe(3)O(4) (PDDA-G/Fe(3)O(4))(n) multilayer films were fabricated with layer-by-layer assembly of negatively charged Fe(3)O(4) nanoparticles (Fe(3)O(4) NPs) and positively charged PDDA-G through the electrostatic interaction to construct a H(2)O(2) chemical sensor. The multilayer films were characterized with UV-vis spectroscopy, atomic force microscopy and cyclic voltammetry. The participation of PDDA-G improved the catalytic ability of Fe(3)O(4) NPs due to its high surface area and excellent electric conductivity. Based on this, the obtained H(2)O(2) chemical sensor exhibited prominent electrocatalytic activity for the detection of H(2)O(2) with a wide linea... Talanta journals http://www.medworm.com/rss/comments.php?id=5437762 Wed, 23 Nov 2011 14:38:03 +0100 5437762 http://www.medworm.com/index.php?rid=5437761&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099675%26dopt%3DAbstract Authors: Pirsa S, Alizadeh N Abstract Polypyrrole (PPy) gas sensor has been prepared by polymerization of pyrrole on surfaces of commercial polymer fibers in the presence of an oxidizing agent. The sensing behavior of PPy gas sensor was investigated in the presence of pyridine derivatives. The resistive responses of the PPy gas sensor to pyridine derivatives were in the order of quinoline>pyridine>4-methyl pyridine and 2-methyl pyridine. The PPy gas sensor was used as gas chromatography (GC) detector and exhibited linear responses to pyridine derivatives in the ranges 40-4000ng. Dispersive liquid-liquid microextraction (DLLME) combined with GC/PPy gas sensor has been developed for simultaneous determination of pyridine derivatives and quinoline. The purposed method was used f... Talanta journals http://www.medworm.com/rss/comments.php?id=5437761 Wed, 23 Nov 2011 14:37:54 +0100 5437761 http://www.medworm.com/index.php?rid=5437760&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099676%26dopt%3DAbstract Authors: Dessuy MB, Kratzer J, Vale MG, Welz B, Dědina J Abstract Antimony is one of the constituents of pewter, an alloy composed of a minimum of 90% tin with the balance being made up with copper, antimony and perhaps some bismuth. A method has been developed to determine Sb in acetic acid leachates from pewter cups. The employed instrumentation, an atomic absorption spectrometer, equipped with a quartz trap-and-atomizer device, is simple and relatively inexpensive with low running costs. Interferences due to the presence of tin and ways to control them were investigated in detail. The applied approach made possible to overcome potentially serious interference of Sn leached from the cup material (which was shown to take place in the atomizer), by a combination of (i) high concen... Talanta journals http://www.medworm.com/rss/comments.php?id=5437760 Wed, 23 Nov 2011 14:37:44 +0100 5437760 http://www.medworm.com/index.php?rid=5437759&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099677%26dopt%3DAbstract Authors: Gao Y, De Canck E, Leermakers M, Baeyens W, Van Der Voort P Abstract 3-Mercaptopropyl functionalized SBA-15 (SH-SBA) and 3-mercaptopropyl functionalized ethenylene bridged periodic mesoporous organosilica (SH-PMO) were included in a Diffusive Gradients in Thin film (DGT) probe and compared to similar commercially available resins also containing thiol functional groups, such as Sumichelate Q10R (SQR) and 3-mercaptopropyl functionalized silica gel (SH-KG), and also to the Chelex-100 resin for the determination of labile Hg concentrations. An agarose gel was used as the diffusive gel because the classic polyacrylamide gel shows more than 20% of Hg adsorption. According to our results, the Chelex-100 resin presents a much lower affinity for Hg than the thiol based resins. The... Talanta journals http://www.medworm.com/rss/comments.php?id=5437759 Wed, 23 Nov 2011 14:37:34 +0100 5437759 http://www.medworm.com/index.php?rid=5437758&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099678%26dopt%3DAbstract Authors: Peñalver R, Campillo N, Hernández-Córdoba M Abstract Two procedures for the simultaneous determination of organolead (tetraethyllead, triethyllead and trimethyllead) and organomanganese compounds (cyclopentadienyl manganese tricarbonyl (CMT) and methylcyclopentadienyl manganese tricarbonyl (MMT)) are studied. Both procedures involve sample preconcentration by solid-phase microextraction and capillary gas chromatography coupled to atomic emission detection, the main difference being the derivatizing agent used for the ionic alkylated lead species: sodium tetrapropylborate (NaBPr(4)) and sodium tetraphenylborate (NaBPh(4)). The parameters affecting the derivatization and preconcentration steps, chromatographic separation as well as detection of the compounds were optimize... Talanta journals http://www.medworm.com/rss/comments.php?id=5437758 Wed, 23 Nov 2011 14:37:24 +0100 5437758 http://www.medworm.com/index.php?rid=5437755&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099679%26dopt%3DAbstract We report that benzodipyrido[3,2-a:2',3'-c]phenazine (BDPPZ) and 3,6-dimethylbenzodipyrido-[3,2-a:2',3'-c]phenazine (DM-BDPPZ) provide independent fluorescent and electrochemical signal transductions in the presence of the organophosphorus (OP) pesticides; fenthion, malathion and ethion. The presence of the methyl groups at the 3 and 6 positions in DM-BDPPZ was found to significantly influence the sensor performance. The difference in the fluorescence and electrochemical signals produced by the interaction of the sensor compound with each of the OP pesticides provides a means for differentiating between the three pesticides. Detection limits of 10(-8)M, 10(-9) and 10(-12)M were obtained for fenthion, malathion and ethion, respectively. Due to the high sensitivity and ability to minimize fa... Talanta journals http://www.medworm.com/rss/comments.php?id=5437755 Wed, 23 Nov 2011 14:37:14 +0100 5437755 http://www.medworm.com/index.php?rid=5437751&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099680%26dopt%3DAbstract In this study, functionalized polysulfone membrane has been utilized as a sorbent for the extraction of chlorinated hydrocarbons (CHCs) in water samples. Two different functionalized polysulfones (i) phosphonic acid functionalized polysulfone (PPSU-A) with different forms (cross-linked and non cross-linked) membranes and (ii) phosphonic ester functionalized polysulfone (PPSU-E) with different forms (cross-linked and non cross-linked) were evaluated for the extraction of CHCs in water. A 10ml of spiked water sample was extracted with 50mg piece of the functionalized membrane. After extraction, the membrane was desorbed by organic solvent and the extract was analyzed by gas chromatography-mass spectrometry. Eight CHCs, 1,3,5-trichlorobenzene (1,3,5-TCB), 1,2,3-trichlorobenzene (1,2,3-TCB), 1... Talanta journals http://www.medworm.com/rss/comments.php?id=5437751 Wed, 23 Nov 2011 14:37:04 +0100 5437751 http://www.medworm.com/index.php?rid=5437750&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099681%26dopt%3DAbstract Authors: Hikal WM, Paden JT, Weeks BL Abstract Accurate thermodynamic parameters of thin films of explosives are important for understanding their behavior in the nanometer scale as well as in standoff detection. Using UV-absorbance spectroscopy technique, accurate thermodynamic parameters such as activation energies of sublimation, sublimation rates, and vapor pressures of the explosives cyclotrimethylenetrinitramine (RDX) and 2,4,6-trinitrotoluene (TNT) were determined. The values of these parameters are in excellent agreement with those reported using traditional experiments based on gravimetry. In terms of the Clapeyron equation, the dependence of RDX and TNT vapor pressures on temperature can be described by the relations LnP (Pa)=39.6-15459/T (K) and LnP (Pa)=34.9-12058/T (K)... Talanta journals http://www.medworm.com/rss/comments.php?id=5437750 Wed, 23 Nov 2011 14:36:54 +0100 5437750 http://www.medworm.com/index.php?rid=5437749&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099682%26dopt%3DAbstract Authors: Maj-Zurawska M, Lewenstam A Abstract Membrane ion-selective magnesium electrodes are commonly used to determine ionized magnesium concentration in blood serum and intracellular fluid by potentiometric clinical analyzers. The selectivity of these electrodes against calcium ion is typically insufficient to avoid calcium interference in blood serum analysis. For this reason the selectivity coefficient for calcium ion has to be studied to make possible any mathematical corrections for calcium ion influence. Existing methods relate to the thermodynamic concept of ISE response which suggest a single constant value of the selectivity coefficient and slope that are stable over the concentration ranges of calcium and magnesium ions in the samples. Unfortunately, this rarely happens... Talanta journals http://www.medworm.com/rss/comments.php?id=5437749 Wed, 23 Nov 2011 14:36:44 +0100 5437749 http://www.medworm.com/index.php?rid=5437748&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099683%26dopt%3DAbstract Authors: Li F, Zhou R, Zhao K, Chen H, Hu Y Abstract A novel magnetic electrochemical immunosensor has been developed for the detection of pseudorabies virus antibody in swine serum. The magnetic glass carbon electrode was fabricated to manipulate magnetic beads for the direct sensing applications. Magnetic beads were employed as the platforms for the immobilization and immunoreaction process, and gold nanoparticles were chosen as electroactive labels for the electrochemical detection. The parameters concerning the assay strategy were carefully investigated. Under the optimal conditions, the linear response range of pseudorabies virus antibody dilution ratio (standard positive serum) was 1:250 to 1:1000 with a detection limit of 1:1000. Finally, this developed immunoassay method wa... Talanta journals http://www.medworm.com/rss/comments.php?id=5437748 Wed, 23 Nov 2011 14:36:34 +0100 5437748 http://www.medworm.com/index.php?rid=5437741&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099684%26dopt%3DAbstract We describe a method for expanding the linear dynamic range for multiple reaction monitoring (MRM) in quantitative liquid chromatography/tandem mass spectrometry (LC-MS/MS) using additional transitions for isotopologues. In addition to the regular transition for the highest possible sensitivity, a transition corresponding to the less abundant isotopologue ions was utilized. This decreases saturation at the ion detector; the sensitivity reduction increases the upper dynamic limit. We demonstrated this for a rat plasma assay for a candidate flavor compound; the linear dynamic range increased by an order of magnitude from 3 to 6000ng/mL with the regular MRM alone to 3-60,000ng/mL using additionally the isotopologue transition. PMID: 22099684 [PubMed - in process] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=5437741 Wed, 23 Nov 2011 14:36:24 +0100 5437741 http://www.medworm.com/index.php?rid=5437737&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22099685%26dopt%3DAbstract Comments on "Recognition of molecularly imprinted polymers for a quaternary alkaloid of berberine". Talanta. 2011 Dec 15;87:311 Authors: Yuh-Shan H PMID: 22099685 [PubMed - in process] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=5437737 Wed, 23 Nov 2011 14:36:14 +0100 5437737 http://www.medworm.com/index.php?rid=5415887&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063505%26dopt%3DAbstract Authors: Christian G PMID: 22063505 [PubMed - in process] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=5415887 Sun, 30 Oct 2011 04:00:00 +0100 5415887 http://www.medworm.com/index.php?rid=5415886&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063506%26dopt%3DAbstract Authors: Buszewski B, Michel M PMID: 22063506 [PubMed - in process] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=5415886 Sun, 30 Oct 2011 04:00:00 +0100 5415886 http://www.medworm.com/index.php?rid=5415885&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063507%26dopt%3DAbstract Authors: Tankiewicz M, Fenik J, Biziuk M Abstract The intensification of agriculture means that increasing amounts of toxic organic and inorganic compounds are entering the environment. The pesticides generally applied nowadays are regarded as some of the most dangerous contaminants of the environment. Their presence in the environment, especially in water, is hazardous because they cause human beings to become more susceptible to disease. For these reasons, it is essential to monitor pesticide residues in the environment with the aid of all accessible analytical methods. The analysis of samples for the presence of pesticides is problematic, because of the laborious and time-consuming operations involved in preparing samples for analysis, which themselves may be a source of additio... Talanta journals http://www.medworm.com/rss/comments.php?id=5415885 Sun, 30 Oct 2011 04:00:00 +0100 5415885 http://www.medworm.com/index.php?rid=5415884&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063508%26dopt%3DAbstract Authors: Oracz J, Nebesny E, Zyżelewicz D Abstract Methods applied in acrylamide quantification in foods have been reviewed in this paper. Novel analytical techniques like capillary electrophoresis (CE), immunoenzymatic test (ELISA) and electrochemical biosensors, which can replace traditional methods like high performance liquid chromatography (HPLC) and gas chromatography (GC) were presented. Short time of analysis and high resolution power of electrophoretic techniques caused that they became routinely used in food analysis apart from high performance liquid chromatography and gas chromatography. Application of modern chromatography methods like ultra performance liquid chromatography (UPLC) in acrylamide quantification considerably shortened the time of analysis and decreased ... Talanta journals http://www.medworm.com/rss/comments.php?id=5415884 Sun, 30 Oct 2011 04:00:00 +0100 5415884 http://www.medworm.com/index.php?rid=5415883&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063509%26dopt%3DAbstract Authors: Dąbrowska M, Starek M, Skuciński J Abstract Lipophilicity properties have long been considered a vital component of drug discovery and development, providing insight into the role of molecular properties in the biological activity of known and new compounds. An extensive survey of the literature published in analytical and pharmaceutical chemistry journals has been conducted. Separation, optical, electrochemical and calculation methods which were developed and used for determination of lipophilicity non-steroidal anti-inflammatory agents and cephalosporin antibiotics in drugs and biological materials, have been reviewed. This review covers over 100 miscellaneous methods. Presented review highlighted some recent developments and new techniques that have been used in the l... Talanta journals http://www.medworm.com/rss/comments.php?id=5415883 Sun, 30 Oct 2011 04:00:00 +0100 5415883 http://www.medworm.com/index.php?rid=5415882&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063510%26dopt%3DAbstract Authors: López-García I, Rivas RE, Hernández-Córdoba M Abstract A procedure for the determination of inorganic arsenic (III, V) and antimony (III, V) in water samples by using a miniaturized solid-phase extraction with carbon nanotubes followed by electrothermal atomic absorption measurement is proposed. The trivalent species are first complexed with ammonium pyrrolidinedithiocarbamate, next retained in a mini-column containing nanotubes and then eluted by means of a plug of an ammonia solution. The atomizer is impregnated with a tungsten salt which acts as an effective chemical modifier during the heating cycle. Total inorganic arsenic and antimony are determined after the reduction of the pentavalent forms with an ammonium iodide solution. Pentavalent arsenic and antimony are... Talanta journals http://www.medworm.com/rss/comments.php?id=5415882 Sun, 30 Oct 2011 04:00:00 +0100 5415882 http://www.medworm.com/index.php?rid=5415881&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063511%26dopt%3DAbstract Authors: Rajabi Khorrami A, Narouenezhad E Abstract Molecularly imprinted monolithic fibers were synthesized and evaluated for solid-phase microextraction (SPME) of acetaldehyde from head-space of beverages stored in poly(ethylene terephthalate) (PET) bottles. The fibers were prepared by co-polymerization of methacrylic acid and ethylene glycole diethacrylate as functional monomer and cross-linker, respectively. Acetaldehyde was used as template molecule during polymerization process, in order to leave specific cavities after leaching off from the co-polymer. Narrow bore (i.d. 100μm) glass capillaries as molds were filled with polymerization mixture containing cross linker, functional monomer, template molecule, initiator and porogen solvent. This mixture is then polymerized to fo... Talanta journals http://www.medworm.com/rss/comments.php?id=5415881 Sun, 30 Oct 2011 04:00:00 +0100 5415881 http://www.medworm.com/index.php?rid=5415880&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063512%26dopt%3DAbstract Authors: Bradley MM, Siperko LM, Porter MD Abstract This paper introduces a method for the determination of inorganic arsenite [As(III)] in water at low μgL(-1) by a sorption-photometric method known as colorimetric-solid phase extraction (C-SPE). The method relies on the selective extraction and concentration of an analyte on a reagent-impregnated SPE membrane, followed by direct detection of the extracted colored complex by a handheld diffuse reflectance spectrophotometer (DRS) operating in the visible spectral region. The well-established chemistry of the classic redox titrimetric method for molecular iodine (I(2)) standardization by arsenious oxide (As(2)O(3)) serves as the basis for this analysis. I(2), which is added to the aqueous sample in an excess with respect to the ana... Talanta journals http://www.medworm.com/rss/comments.php?id=5415880 Sun, 30 Oct 2011 04:00:00 +0100 5415880 http://www.medworm.com/index.php?rid=5415879&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063513%26dopt%3DAbstract Authors: Leiva G MA, Araya C C, Mancilla C, Seguel R, Norris JE Abstract A comparison of the ozone primary reference standard photometer serial number 45 (SRP45) against the National Institute of Standards and Technology (NIST) instruments, serial number 0 (SRP0) and 2 (SRP2), has been performed in order to establish the traceability and comparability of ozone measurements made by the Chilean atmospheric science community. A complete uncertainty budget was developed for SRP45, using a GUM approach. The results of the comparisons allow us to conclude that SRP45, SRP0 and SRP2 are comparable according to internationals criteria over an ozone mole fraction range of 0nmolmol(-1) to at least 500nmolmol(-1). The official result for the validation of SRP45 is x(ozone)(SRP45)=[0.013+0.9980... Talanta journals http://www.medworm.com/rss/comments.php?id=5415879 Sun, 30 Oct 2011 04:00:00 +0100 5415879 http://www.medworm.com/index.php?rid=5415878&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063514%26dopt%3DAbstract Authors: Silva CL, Pereira J, Wouter VG, Giró C, Câmara JS Abstract This manuscript describes the development and validation of an ultra-fast, efficient, and high throughput analytical method based on ultra-high performance liquid chromatography (UHPLC) equipped with a photodiode array (PDA) detection system, for the simultaneous analysis of fifteen bioactive metabolites: gallic acid, protocatechuic acid, (-)-catechin, gentisic acid, (-)-epicatechin, syringic acid, p-coumaric acid, ferulic acid, m-coumaric acid, rutin, trans-resveratrol, myricetin, quercetin, cinnamic acid and kaempferol, in wines. A 50-mm column packed with 1.7-μm particles operating at elevated pressure (UHPLC strategy) was selected to attain ultra-fast analysis and highly efficient separations. In order to re... Talanta journals http://www.medworm.com/rss/comments.php?id=5415878 Sun, 30 Oct 2011 04:00:00 +0100 5415878 http://www.medworm.com/index.php?rid=5415877&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063515%26dopt%3DAbstract Authors: Magnier A, Billon G, Louis Y, Baeyens W, Elskens M Abstract A procedure to determine lead and zinc by anodic stripping voltammetry and copper by cathodic stripping voltammetry in natural river samples was developed and validated. Cu determination involves the adsorption of Cu complexes with 8-hydroxyquinoline (oxine) onto a hanging mercury drop electrode. All samples were studied at natural pH and following optimal conditions were found: an accumulation step at -1.3V (all potential values in the paper are given versus the Ag/AgCl, [KCl]=3M reference electrode) during 30s for determination of Zn contents and at -0.7V during 60s for determination of Pb contents. Concerning Cu analysis, the optimal oxine concentration was found to be 10(-5)M with a deposition potential of -1.... Talanta journals http://www.medworm.com/rss/comments.php?id=5415877 Sun, 30 Oct 2011 04:00:00 +0100 5415877 http://www.medworm.com/index.php?rid=5415876&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063516%26dopt%3DAbstract Authors: Lee MH, Park JH, Oh SY, Ahn HJ, Lee CH, Song K, Lee MS Abstract A simple and reliable separation method of plutonium and uranium was developed using extraction chromatographic techniques. Using the separation method of plutonium and uranium developed in this study, recoveries of plutonium and uranium were compared with those by commercial separation methods of Pu and U. The redox reactions of hydrogen peroxide with plutonium in a nitric acid medium were investigated by UV-vis-NIR absorption spectroscopic techniques. The separation method of Pu and U isotopes with the UTEVA resin updated in this study could be effective to measure quantitatively nano- and picogram amounts of uranium and plutonium in swipe samples using isotope dilution thermal ionization mass spectrometry (... Talanta journals http://www.medworm.com/rss/comments.php?id=5415876 Sun, 30 Oct 2011 04:00:00 +0100 5415876 http://www.medworm.com/index.php?rid=5415875&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063517%26dopt%3DAbstract In this study, a stir rod sorptive extraction (SRSE) adsorbent material was prepared by coating poly(4-vinylpyridine-co-ethylene glycol dimethacrylate) [poly(VP-co-EDMA)] monolithic polymer on stir rod, and then applied to the extraction of three non-steroidal anti-inflammatory drugs (NSAIDs) in environmental aqueous samples. The preparation conditions of monolithic material such as the amount of porogen and the ratio of functional monomer to cross-linker were investigated. To achieve the best extraction efficiency, several parameters, including pH value of sample solution, salt concentration in sample matrix, desorption solvent, extraction time, and desorption time, were optimized. By combining SRSE and high performance liquid chromatography with ultraviolet detector, a SRSE-HPLC/UV metho... Talanta journals http://www.medworm.com/rss/comments.php?id=5415875 Sun, 30 Oct 2011 04:00:00 +0100 5415875 http://www.medworm.com/index.php?rid=5415874&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063518%26dopt%3DAbstract Authors: Alhooshani K, Basheer C, Kaur J, Gjelstad A, Rasmussen KE, Pedersen-Bjergaard S, Lee HK Abstract For the first time, haloacetic acids and aromatic acetic acids were extracted from wastewater samples using electromembrane extraction (EME). A thin layer of toluene immobilized on the walls of a polypropylene membrane envelope served as an artificial supported liquid membrane (SLM). The haloacetic acids (HAAs) (chloroacetic acid, dichloroacetic acid, and trifluoroacetic acid) and aromatic acetic acids (phenylacetic acid and p-hydroxyphenylacetic acid) were extracted through the SLM and into an alkalized aqueous buffer solution. The buffer solution was located inside the membrane envelope. The electrical potential difference sustained over the membrane acted as the driving forc... Talanta journals http://www.medworm.com/rss/comments.php?id=5415874 Sun, 30 Oct 2011 04:00:00 +0100 5415874 http://www.medworm.com/index.php?rid=5415873&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063519%26dopt%3DAbstract Authors: Zhang J, Cheng R, Tong S, Gu X, Quan X, Liu Y, Jia Q, Jia J Abstract In this work, we synthesized TiO(2)-graphene composite as a novel preconcentration material. It was enclosed in a microcolumn in the on-line flow injection system to adsorb trace light (La), medium (Tb), and heavy (Ho) rare earth elements (REEs) prior to their determinations by microwave plasma torch-atomic emission spectrometry (MPT-AES). Various experimental parameters, such as sample loading time, sample flow rate, sample pH, eluent flow rate, eluent concentration, and interfering ions, were investigated systematically. Under the optimum conditions, the detection limits (three times of standard deviations of blank by 7 reiterations) of La, Tb, and Ho were found to be 2.2, 1.6, and 2.8μgL(-1), with enr... Talanta journals http://www.medworm.com/rss/comments.php?id=5415873 Sun, 30 Oct 2011 04:00:00 +0100 5415873 http://www.medworm.com/index.php?rid=5415872&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063520%26dopt%3DAbstract Authors: Modi NR, Patel B, Patel MB, Menon SK Abstract A highly selective and sensitive PVC membrane, containing phenylurea substituted calix[4]arene was found to be a suitable ionophore for monohydrogen phosphate (HPO(4)(2-)) ions that exhibited a Nernstian response (with a slope of -29.4±0.3mVdecade(-1)). The working concentration range of the electrode was 6.0×10(-8)-1.0×10(-1)molL(-1) with a detection limit of 2.0×10(-8)molL(-1). The response time of the sensor in the whole concentration range is very short (<8s), with a considerable lifetime of at least 15 weeks. The sensor possesses the advantages of short response time, low detection limit and a high selectivity towards a large number of inorganic anions. The developed sensor was used as an indicator electrode in pote... Talanta journals http://www.medworm.com/rss/comments.php?id=5415872 Sun, 30 Oct 2011 04:00:00 +0100 5415872 http://www.medworm.com/index.php?rid=5415871&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063521%26dopt%3DAbstract Authors: Sahan S, Sahin U Abstract A novel Pb(II) analysis in dialysis concentrates and seawater samples has been developed with on-line separation and preconcentration system coupled with electrothermal atomic absorption spectrometer (FI-ETAAS). Lewatit Monoplus TP207 imminodiacetat chelating resin was used for separation and preconcentration of Pb(II) ions at pH 4.0. The influence of the analytical parameters such as type of eluent, flow rate of eluent and sample, eluent volume and matrix ions were investigated. W-Rh coated furnace was used as the atomization site. A preconcentration factor of 14 and a detection limit (3s/b) of 12ngL(-1), along with the sampling frequency of 21h(-1) were achieved with a 170s sample loading time and with 2.8mL sample consumption. The relative stan... Talanta journals http://www.medworm.com/rss/comments.php?id=5415871 Sun, 30 Oct 2011 04:00:00 +0100 5415871 http://www.medworm.com/index.php?rid=5415870&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063522%26dopt%3DAbstract Authors: Wang J, Banerji S, Menegazzo N, Peng W, Zou Q, Booksh KS Abstract Molecularly imprinted hydrogel membranes were developed and evaluated for detection of small analytes via surface plasmon resonance spectroscopy. Imprinting of glucose phosphate barium salt into a poly(allylamine hydrochloride) network covalently bound to gold surfaces yielded a selective sensor for glucose. Optimization of relative amounts of chemicals used for preparation of the hydrogel was performed to obtain highest sensitivity. Addition of gold nanoparticles into the hydrogel matrix significantly amplified its response and sensitivity due to the impact of gold nanoparticles on the refractive index of the sensing layer. Evaluation of its selectivity showed that the sensor displayed preferential recognit... Talanta journals http://www.medworm.com/rss/comments.php?id=5415870 Sun, 30 Oct 2011 04:00:00 +0100 5415870 http://www.medworm.com/index.php?rid=5415869&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063523%26dopt%3DAbstract Authors: Piao X, Bi J, Yang C, Wang X, Wang J, Li D Abstract The gas purge microsyringe extraction (GP-MSE) technique offers quantitative and simultaneous extraction, and rapid gas chromatographic-mass spectrometric determination of volatile and semivolatile chemicals is possible. To simplify the application, a new automatic temperature control system was developed here. Stable heating and cooling over a wide range of temperatures were achieved using a micro-heater and thermoelectric cooler under varying gas flow conditions. Temperatures could be accurately controlled in the range 20-350°C (heating) and 20 to -4°C (cooling). Temperature effects on the extraction performance of the GP-MSE were experimentally investigated by comparing the recoveries of polycyclic aromatic hydrocarb... Talanta journals http://www.medworm.com/rss/comments.php?id=5415869 Sun, 30 Oct 2011 04:00:00 +0100 5415869 http://www.medworm.com/index.php?rid=5415868&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063524%26dopt%3DAbstract Authors: Harvey SD, Wright BW Abstract Tax-free diesel fuel is intended for off-road uses such as agricultural operations, but illicit use of this fuel does occur and is a convenient way of evading payment of excise taxes. Current enforcement to prevent this practice involves visual inspection for the red azo dye added to the fuel to indicate its tax-free status. This approach, while very effective, has shortcomings such as the invasive nature of the tests and/or various deceptive tactics applied by tax evaders. A test designed to detect illicit dyed-fuel use by analyzing the vehicle exhaust would circumvent these shortcomings. This paper describes the development of a simple color spot test designed to detect the use of tax-free (i.e., dyed) fuel by analyzing the engine exhaust. D... Talanta journals http://www.medworm.com/rss/comments.php?id=5415868 Sun, 30 Oct 2011 04:00:00 +0100 5415868 http://www.medworm.com/index.php?rid=5415867&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063525%26dopt%3DAbstract In this report, we presented a new method to fabricate TiO(2) nanotube (TiO(2) NT) arrays modified with cupric oxide (CuO) nanofibers, getting a novel TiO(2) NT arrays composition electrode for sensitive nonenzymatic glucose detection. For the preparation of CuO nanofibers, Cu nanoparticles were firstly electrodeposited onto the TiO(2) NT arrays, and then oxidized to CuO nanofibers followed by annealing in air. The CuO nanofibers modified TiO(2) NT (CuO/TiO(2) NT) arrays electrode for electrocatalytic detection of glucose was investigated by cyclic voltammetry and chronoamperometry in 0.10M NaOH solution. The linear range of detection of glucose extended up to 2.0mM (R=0.997, n=10) at a potential of 0.50V (vs. SCE). The sensitivity was 79.79μAcm(-2)mM(-1), and the detection limit was 1μM... Talanta journals http://www.medworm.com/rss/comments.php?id=5415867 Sun, 30 Oct 2011 04:00:00 +0100 5415867 http://www.medworm.com/index.php?rid=5415866&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063526%26dopt%3DAbstract Authors: Huang H, Xu M, Gao Y, Wang G, Su X Abstract In this paper, a sensitive and simple detecting system was developed for quantitative analysis of both hydroquinone (H(2)Q) and hydrogen peroxide (H(2)O(2)), based on the successful combination of horse radish peroxidase (HRP) and water-soluble conjugate fluorescence polymers PPESO(3). In the presence of HRP and H(2)O(2), H(2)Q could be oxidized to 1,4-benzoquinone (BQ), an intermediate, which plays the main role in the enhanced quenching of the photoluminescence (PL) intensity of PPESO(3). The quenching PL intensity of PPESO(3) (I(0)/I) was proportional to the concentration of H(2)Q and H(2)O(2) in the range of 1.0×10(-6) to 2.0×10(-3)mol/L (R(2)=0.996) and 6.0×10(-6) to 2.0×10(-3)mol/L (R(2)=0.999), respectively. The detect... Talanta journals http://www.medworm.com/rss/comments.php?id=5415866 Sun, 30 Oct 2011 04:00:00 +0100 5415866 http://www.medworm.com/index.php?rid=5415865&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063527%26dopt%3DAbstract Authors: Wang Z, Zong S, Chen H, Wu H, Cui Y Abstract A kind of fluorescent dye-doped, silica-coated Au aggregates was fabricated using reverse microemulsion method, which shows both strong fluorescence and intense surface enhanced Raman scattering (SERS) signals. Such a composite nanoparticle is composed of a SERS core as silica-coated Au aggregates and a fluorescent shell as dye-doped silica shell. Being prepared through reverse microemulsion method, the SERS core exhibits a sphere shape and a uniform size. Compared with a silica-coated single Au nanoparticle, our presented SERS core shows a greatly increased SERS intensity due to the Au aggregates, which is formed by simply mixing the SERS reporters and Au nanoparticles. When being excited at different wavelengths as 515nm and 6... Talanta journals http://www.medworm.com/rss/comments.php?id=5415865 Sun, 30 Oct 2011 04:00:00 +0100 5415865 http://www.medworm.com/index.php?rid=5415864&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063528%26dopt%3DAbstract Authors: Ballesta-Claver J, Salinas Velázquez P, Valencia-Mirón MC, Capitán-Vallvey LF Abstract A poly(luminol-3,3',5,5'-tetramethylbenzidine) copolymer manufactured by electropolymerization on screen-printed gold electrodes greatly improves the electrochemiluminescence of hydrogen peroxide. Cholesterol oxidase was immobilized on the surface of a poly(luminol-3,3',5,5'-tetramethylbenzidine) screen-printed cell modified with chitosan to prepare an ECL biosensor for cholesterol. Working under the optimized conditions, the linear dynamic range of cholesterol was 2.4×10(-5)-1.0×10(-3)M with a limit of detection of 7.3×10(-6)M and a precision of 10.3% (5.0×10(-4)M, n=5) expressed as relative standard deviation. This biosensor was applied to the determination of total cholesterol ... Talanta journals http://www.medworm.com/rss/comments.php?id=5415864 Sun, 30 Oct 2011 04:00:00 +0100 5415864 http://www.medworm.com/index.php?rid=5415863&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063529%26dopt%3DAbstract Authors: Anizan S, Bichon E, Di Nardo D, Monteau F, Cesbron N, Antignac JP, Le Bizec B Abstract The use of anabolic agents in food producing animals is prohibited within the European Union since 1988. The illegal use of natural steroid hormones control is however still a current challenge, especially regarding the limitations of existing screening methods. In this context, the present study aimed to develop a new screening approach based on the emerging 'untargeted profiling' concept, but with a special emphasis on steroids phase II conjugated metabolites, in the scope of revealing potential biomarkers signing a fraudulent administration of 4-androstenedione. After extraction and separation of the urinary glucuronide and sulfate steroid fractions, each one was analyzed separately b... Talanta journals http://www.medworm.com/rss/comments.php?id=5415863 Sun, 30 Oct 2011 04:00:00 +0100 5415863 http://www.medworm.com/index.php?rid=5415862&cid=s_36096_59_f&fid=36096&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D22063530%26dopt%3DAbstract Authors: Rigueira JC, Rodrigues MI, Gloria MB Abstract Polyamines play an important role as growth promoters, in the maturation of the intestinal tract of infants and in the modulation of the immune response; consequently, the importance of polyamines in the diet of infants and adults is well established. However, information on the occurrence and levels of polyamines in cow's milk and milk from other species (including human milk) is contradictory. Furthermore, the methods used for the extraction of amines from these samples vary widely. Therefore, a method for the accurate analysis of amines in milk from different species and in milk products is needed. A sequential strategy of experimental designs was used to optimize the analytical extraction of polyamines from milk. The depend... Talanta journals http://www.medworm.com/rss/comments.php?id=5415862 Sun, 30 Oct 2011 04:00:00 +0100 5415862