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. Sat, 20 Mar 2010 15:58:40 +0100 http://www.medworm.com/index.php?rid=3276784&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%3D20152382%26dopt%3DAbstract Authors: El-Shahawi MS, Hamza A, Bashammakh AS, Al-Saggaf WT Recent years have seen an upsurge of interest in developing low cost and reliable methods for the detection and precise determination of ultra-trace concentrations of persistent organic pollutants (POPs), because of their bioaccumulation, transformation and toxicity. Therefore, a comprehensive review with 108 references referring to the distribution, source, accumulation, transformation, types and toxicity of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) is presented. The review also aims to highlight on the current best practices for the analysis of PCBs and OCPs. Moreover, with the signing of the Stockholm convention on POPs and the development of global monitoring programs, there is an increased nee... Talanta journals http://www.medworm.com/rss/comments.php?id=3276784 Wed, 17 Feb 2010 08:42:35 +0100 3276784 http://www.medworm.com/index.php?rid=3276782&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%3D20152383%26dopt%3DAbstract Authors: van Staden JF, Stefan-van Staden RI Porphyrins and metalloporphyrins fulfil a very important role in the metabolism of living organisms through biological pigments or biochromes and are therefore also employed in numerous applications in analytical chemistry. In flow-injection analysis the role of porphyrins and metalloporphyrins are centered as either that of analyte or that of a reagent or modifier in the determination of other species. This paper covers the attributes of porphyrin and metallophorphyrin complexes as enhancements in chemical analysis in flow-injection systems and points out the advantages and disadvantages in the implementation thereof. PMID: 20152383 [PubMed - as supplied by publisher] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=3276782 Wed, 17 Feb 2010 08:42:31 +0100 3276782 http://www.medworm.com/index.php?rid=3276780&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%3D20152384%26dopt%3DAbstract Authors: Hill AA, Lipert RJ, Porter MD The increase in bacterial resistance to antibiotics has led to resurgence in the use of silver as a biocidal agent in applications ranging from washing machine additives to the drinking water treatment system on the International Space Station (ISS). However, growing concerns about the possible toxicity of colloidal silver to bacteria, aquatic organisms and humans have led to recently issued regulations by the US EPA and FDA regarding the usage of silver. As part of an ongoing project, we have developed a rapid, simple method for determining total silver, both ionic (silver(I)) and colloidal, in 0.1-1mg/L aqueous samples, which spans the ISS potable water target of 0.3-0.5mg/L (total silver) and meets the US EPA limit of 0.1mg/L in drinking water.... Talanta journals http://www.medworm.com/rss/comments.php?id=3276780 Wed, 17 Feb 2010 08:42:28 +0100 3276780 http://www.medworm.com/index.php?rid=3276778&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%3D20152385%26dopt%3DAbstract Authors: López-Darias J, Germán-Hernández M, Pino V, Afonso AM Two liquid-phase microextraction procedures: single-drop microextraction (SDME) and dispersive liquid-liquid microextraction (DLLME), have been developed for the determination of several endocrine-disrupting phenols (EDPs) in seawaters, in combination with high-performance liquid chromatography (HPLC) with UV detection. The EDPs studied were bisphenol-A, 4-cumylphenol, 4-tertbutylphenol, 4-octylphenol and 4-n-nonylphenol. The optimized SDME method used 2.5muL of decanol suspended at the tip of a micro-syringe immersed in 5mL of seawater sample, and 60min for the extraction time. The performance of the SDME is characterized for average relative recoveries of 102+/-11%, precision values (RSD)<9.4% (spiked le... Talanta journals http://www.medworm.com/rss/comments.php?id=3276778 Wed, 17 Feb 2010 08:42:25 +0100 3276778 http://www.medworm.com/index.php?rid=3276776&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%3D20152386%26dopt%3DAbstract Authors: Hui Y, Zhou L, Chen XG In this paper, a rapid and sensitive method for the determination of ammonia and 22 aliphatic amines derivatized was established by cyclodextrin (CD) modified micellar electrokinetic chromatography with laser-induced fluorescence detection using 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole as a derived reagent. By a series of unvaried studies, the best conditions were selected using 20mM tetraborate (pH 9.70) containing 25mM SDS, 7mM beta-CD, 10% acetonitrile, 0.5M urea, and applied voltage 25kV. Under the optimum conditions, ammonia and 22 aliphatic amines were separated successfully in 19min. The signal response was linear over three-order of concentrations. The intra-day and inter-day relative standard deviations (RSD) were less than 0.81% and 1.00% for mi... Talanta journals http://www.medworm.com/rss/comments.php?id=3276776 Wed, 17 Feb 2010 08:42:22 +0100 3276776 http://www.medworm.com/index.php?rid=3276774&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%3D20152387%26dopt%3DAbstract Authors: Wang C, Wang J, Liu D, Wang Z In this paper, a kind of beta-amyloid peptide (Abeta1-16) conjugated gold nanoparticles (Abeta1-16@GNPs) are prepared and employed as colorimetric indicator for studying the interaction of beta-amyloid peptide with metallic ions (e.g. Zn(2+) and Ca(2+)). In the presence of Zn(2+), mono-dispersing Abeta1-16@GNPs enable to form aggregates or attach on the SHG-44 (human glioma cell) cellular surface which results in significant color change of the solution. The experimental results indicate that Zn(2+) can interact with Abeta1-16 and form Zn(2+)-beta-amyloid peptide complexes. In particular, in the presence of Zn(2+), a time-dependent interaction of cells with Abeta1-16@GNPs has been observed that may suggest different expression levels of beta-amylo... Talanta journals http://www.medworm.com/rss/comments.php?id=3276774 Wed, 17 Feb 2010 08:42:18 +0100 3276774 http://www.medworm.com/index.php?rid=3276772&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%3D20152388%26dopt%3DAbstract Authors: Zaijun L, Zhongyun W, Xiulan S, Yinjun F, Peipei C The paper describes a sensitive and highly stable label-free electrochemical impedance immunosensor for the determination of aflatoxin B(1) (AFB(1)), which is based on the formation of silica gel-ionic liquid biocompatible film on the glassy carbon electrode. The electrochemical performances of the sensor were investigated by electrochemical impedance spectroscopy using a Fe(CN)(6)(3-/4-) phosphate buffer solution as base solution for test. As new ionic liquid, 1-amyl-2,3-dimethylimidazolium hexafluorophosphate, offers a very biocompatible microenvironment for AFB(1) antibody, the sensor exhibits good repeatability (RSD=1.2%), sensitive electrochemical impedance response to AFB(1) in the range of 0.1-10ngml(-1) and lowers the ... Talanta journals http://www.medworm.com/rss/comments.php?id=3276772 Wed, 17 Feb 2010 08:42:15 +0100 3276772 http://www.medworm.com/index.php?rid=3276770&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%3D20152389%26dopt%3DAbstract Authors: Bai H, Zhou Q, Xie G, Xiao J Hydrophobic ionic liquid could be dispersed into infinite droplets under driving of high temperature, and then they can aggregate as big droplets at low temperature. Based on this phenomenon a new liquid-phase microextraction for the pre-concentration of lead was developed. In this experiment, lead was transferred into its complex using dithizone as chelating agent, and then entered into the infinite ionic liquid drops at high temperature. After cooled with ice-water bath and centrifuged, lead complex was enriched in the ionic liquid droplets. Important parameters affected the extraction efficiency had been investigated including the pH of working solution, amount of chelating agent, volume of ionic liquid, extraction time, centrifugation time, and... Talanta journals http://www.medworm.com/rss/comments.php?id=3276770 Wed, 17 Feb 2010 08:42:10 +0100 3276770 http://www.medworm.com/index.php?rid=3276768&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%3D20152390%26dopt%3DAbstract Authors: Wang X, Dong P, Yun W, Xu Y, He P, Fang Y A solid-state electrochemiluminescence (ECL) biosensing switch based on special ferrocene-labeled molecular beacon (Fc-MB) has been successfully developed for T4 DNA ligase detection. Such special switch system consisted of two main parts, an ECL substrate and an ECL intensity switch. The ECL substrate was made by modifying the complex of Au nanoparticle and Ruthenium (II) tris-(bipyridine) (Ru(bpy)(3)(2+)-AuNPs) onto Au electrode. A molecular beacon labeled by ferrocene as the ECL intensity switch. The molecular beacon is designed with special base sequence, which could combine with its target biomolecule via the reaction of the repair and recombination of nucleic acids by DNA ligase. During the reaction, the molecular beacon opened i... Talanta journals http://www.medworm.com/rss/comments.php?id=3276768 Wed, 17 Feb 2010 08:42:05 +0100 3276768 http://www.medworm.com/index.php?rid=3276767&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%3D20152391%26dopt%3DAbstract Authors: Song MJ, Hwang SW, Whang D The electrocatalytic activity of a CuO flower-like nanostructured electrode was investigated in terms of its application to enzyme-less amperometric H(2)O(2) sensors. The CuO nanoflowers film was directly formed by chemical oxidation of copper foil under hydrothermal condition and then used as active electrode material of non-enzymatic electrochemical sensors for H(2)O(2) detection under alkaline conditions. The sensitivity of the sensor with CuO nanoflowers electrode was 88.4muA/mMcm(2) with a linear response in the range from 4.25x10(-5) to 4x10(-2)M and a detection limit of 0.167muM (S/N=3). Excellent electrocatalytic activity, large surface-to-volume ratio and efficient electron transport property of CuO nanoflowers electrode have enabled stable ... Talanta journals http://www.medworm.com/rss/comments.php?id=3276767 Wed, 17 Feb 2010 08:41:59 +0100 3276767 http://www.medworm.com/index.php?rid=3276766&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%3D20152392%26dopt%3DAbstract Authors: Jena BK, Raj CR Au nanoparticle (nAu) based electrochemical platform for the amperometric sensing of isoniazid at sub-nanomolar level is developed. The sol-gel derived 3-dimensional silicate network pre-assembled on a conducting substrate is chemically decorated with nAu of 70-100nm by seed-mediated growth approach. The Au nanoseeds are first chemisorbed onto the thiol functional groups of the silicate network and their size was enlarged by hydroxylamine seeding. The nanoparticles efficiently catalyze the oxidation of isoniazid at less positive potential. Large decrease in the overpotential and significant enhancement in the anodic peak current with respect to the polycrystalline Au electrode are observed. The nanoparticle based platform is highly sensitive (4.03+/-0.01nA/nM) ... Talanta journals http://www.medworm.com/rss/comments.php?id=3276766 Wed, 17 Feb 2010 08:41:56 +0100 3276766 http://www.medworm.com/index.php?rid=3276765&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%3D20152393%26dopt%3DAbstract Authors: Noroozifar M, Khorasani-Motlagh M, Taheri A A silver hexacyanoferrate nanoparticles/carbon nanotubes modified glassy carbon electrode was fabricated and then successfully used for the simultaneous determination of ascorbic acid, dopamine and uric acid by cyclic voltammetry. A detailed investigation by transmission electron microscopy (TEM) and electrochemistry was performed in order to elucidate the preparation process and properties of the nanocomposites. The size of silver hexacyanoferrate nanoparticles was examined by TEM around 27nm. Linear calibration plots were obtained over the range of 4.0x10(-6)-7.8x10(-5), 2.4x10(-6)-1.3x10(-4) and 2.0x10(-6)-1.5x10(-4)molL(-1) with detection limits of 4.2x10(-7),1.4x10(-7) and 6.0x10(-8)molL(-1) for ascorbic acid, dopamine and uric ... Talanta journals http://www.medworm.com/rss/comments.php?id=3276765 Wed, 17 Feb 2010 08:41:53 +0100 3276765 http://www.medworm.com/index.php?rid=3276764&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%3D20152394%26dopt%3DAbstract Authors: Widjaja E, Garland M Raman spectra of human nail clippings from various sources were collected and then deconvoluted to obtain the pure component spectra of the underlying constituents present. This blind-deconvolution was performed using a self-modeling curve resolution technique, namely band-target entropy minimization (BTEM). The aim was to simplify the complexity of the Raman spectra and hence to identify the underlying biological molecules in more detail. BTEM analysis could recover 13 pure component Raman spectral estimates from the collected 438 spectra measured from 113 nail samples. Six recovered pure component spectral estimates correspond to proteins or polypeptides that contain various amino acids such as phenylalanine, tyrosine, tryptophan, and cysteine. Two are a... Talanta journals http://www.medworm.com/rss/comments.php?id=3276764 Wed, 17 Feb 2010 08:41:50 +0100 3276764 http://www.medworm.com/index.php?rid=3276763&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%3D20152395%26dopt%3DAbstract Authors: Kuo CH, Lee CW, Lin SC, Tsai IL, Lee SS, Tseng YJ, Kang JJ, Peng FC, Wei-Chu L Aristolochic acids (AAs) are a mixture of structural-related compounds, in which aristolochic acid I (AA I) and aristolochic acid II (AA II) are reported to be correlated with Aristolochic acid nephropathy (AAN). In this work, a rapid and sensitive ultra-high-pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed to determine AA I and AA II in herbal products and biological fluids. By using gradient elution with a mobile phase composed of a mixture of 10mM ammonium formate buffer (pH 3.0) and acetonitrile, AAs could be determined within 10min. Under optimum UHPLC-MS/MS conditions, the limit of detections was 0.14 and 0.26ngmL(-1) for AA I and AA II, respectively. ... Talanta journals http://www.medworm.com/rss/comments.php?id=3276763 Wed, 17 Feb 2010 08:41:47 +0100 3276763 http://www.medworm.com/index.php?rid=3276762&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%3D20152396%26dopt%3DAbstract In this study, using various glycerol aqueous solutions with certain viscosities and densities, the motion time (i.e. floating or sedimentation time) of hybrid polymer beads was experimentally measured and theoretically deduced, and consequently, the apparent density of monodisperse beads can be quickly and easily calculated. The results indicated that the present method provided a more precise way to predict the movement of hybrid beads in aqueous solution compared with the approach for commercial use. This new method can be potentially employed in flow cytometry, suspension stability, and particle analysis systems. PMID: 20152396 [PubMed - as supplied by publisher] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=3276762 Wed, 17 Feb 2010 08:41:45 +0100 3276762 http://www.medworm.com/index.php?rid=3276761&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%3D20152397%26dopt%3DAbstract Authors: Kalimuthu P, John SA This paper describes the simultaneous determination of ascorbic acid (AA), dopamine (DA), uric acid (UA) and xanthine (XN) using an ultrathin electropolymerized film of 2-amino-1,3,4-thiadiazole (p-ATD) modified glassy carbon (GC) electrode in 0.20M phosphate buffer solution (pH 5.0). Bare GC electrode failed to resolve the voltammetric signals of AA, DA, UA and XN in a mixture. On the other hand, the p-ATD modified electrode separated the voltammetric signals of AA, DA, UA and XN with potential differences of 110, 152 and 392mV between AA-DA, DA-UA and UA-XN, respectively and also enhanced their oxidation peak currents. The modified electrode could sense 5muM DA and 10muM each UA and XN even in the presence of 200muM AA. The oxidation currents were increa... Talanta journals http://www.medworm.com/rss/comments.php?id=3276761 Wed, 17 Feb 2010 08:41:42 +0100 3276761 http://www.medworm.com/index.php?rid=3276760&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%3D20152398%26dopt%3DAbstract Authors: Mao L, Yuan R, Chai Y, Zhuo Y, Yang X, Yuan S An effective method for immobilization of Ru(bpy)(3)(2+) on glassy carbon electrode surface (GCE) is developed for the preparation of a novel electrochemiluminescence sensor. First of all, the positively charged Ru(bpy)(3)(2+) is modified on the surface of negatively charged gold nanoparticles (nano-Au) via the electrostatic interactions to obtain the Ru(bpy)(3)(2+)/nano-Au nano-sphere (abbreviate as Ru-AuNPs). Subsequently, the large amount of Ru-AuNPs are immobilized on the multi-wall carbon nanotubes (MWCNTs)-Nafion homogeneous composite coated GCE by dual interaction: firstly, the Nafion, a kind of typical cation-exchange membrane, can absorb the Ru-AuNPs as the enrichment of cation Ru(bpy)(3)(2+) on the Ru-AuNPs surface; secon... Talanta journals http://www.medworm.com/rss/comments.php?id=3276760 Wed, 17 Feb 2010 08:41:39 +0100 3276760 http://www.medworm.com/index.php?rid=3276759&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%3D20152399%26dopt%3DAbstract Authors: Zou HY, Wu HL, Fu HY, Tang LJ, Xu L, Nie JF, Yu RQ Multivariate spectral analysis has been widely applied in chemistry and other fields. Spectral data consisting of measurements at hundreds and even thousands of analytical channels can now be obtained in a few seconds. It is widely accepted that before a multivariate regression model is built, a well-performed variable selection can be helpful to improve the predictive ability of the model. In this paper, the concept of traditional wavelength variable selection has been extended and the idea of variable weighting is incorporated into least-squares support vector machine (LS-SVM). A recently proposed global optimization method, particle swarm optimization (PSO) algorithm is used to search for the weights of variables and the hy... Talanta journals http://www.medworm.com/rss/comments.php?id=3276759 Wed, 17 Feb 2010 08:41:37 +0100 3276759 http://www.medworm.com/index.php?rid=3276758&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%3D20152400%26dopt%3DAbstract We describe the procedure developed for the simultaneous detection and quantification of angiotensin II and angiotensin-(1-7), by capillary zone electrophoresis with UV detection by photodiode-array, at a wavelength of 200nm, in the plasma and urine from hypertensive rats. Optimal separation was achieved with a 100mM boric acid+3mM tartaric acid+10fM gold (III) chloride electrolyte solution at pH 9.80. The applied voltage was 30kV and the capillary temperature was kept constant at 20 degrees C. The method was over the concentration range of 0.01-500pmol/mL. All determination coefficients were higher or equal to 0.9985. Limits of detection and quantification for angiotensin II were 0.0110pmol/mL (S/N=3) and 0.0195pmol/mL (S/N=5), respectively. While for angiotensin-(1-7), the limits were 0.... Talanta journals http://www.medworm.com/rss/comments.php?id=3276758 Wed, 17 Feb 2010 08:41:34 +0100 3276758 http://www.medworm.com/index.php?rid=3276757&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%3D20152401%26dopt%3DAbstract Authors: Liu Y, Hoshina K, Haginaka J Three monodispersed, molecularly imprinted polymers (MIPs) for cinchonidine (CD) have been synthesized by precipitation polymerization. MIP1 was prepared using methacrylic acid (MAA) as a functional monomer and divinylbenzene (DVB) as a cross-linker and MIP2 was prepared with further addition of 2-hydroxyethyl methacrylate (HEMA) as a co-monomer. For the preparation of MIP3, core-shell type MIP, monodispersed DVB homopolymers, which are prepared by precipitation polymerization, were used as a core and CD-imprinted MAA-DVB copolymer phases were coated onto the core. Three MIPs synthesized gave monodispersed, spherical beads in micrometer sizes. The binding characteristics and molecular recognition properties of MIP1-3 were examined by Scatchard anal... Talanta journals http://www.medworm.com/rss/comments.php?id=3276757 Wed, 17 Feb 2010 08:41:31 +0100 3276757 http://www.medworm.com/index.php?rid=3276756&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%3D20152402%26dopt%3DAbstract Authors: Xiao C, Chu X, Wu B, Pang H, Zhang X, Chen J Polymerized ionic liquid-wrapped carbon nanotubes (PIL-CNTs) were firstly designed for direct electrochemistry and biosensing of redox proteins. The CNTs were coated successfully with polymerized ionic liquid (PIL) layer, as verified by transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy. The PIL-CNTs were dispersed better in water and showed superior electrocatalysis toward O(2) and H(2)O(2) comparing to pristine CNTs and the mixture of IL monomer and CNTs. With glucose oxidase (GOD) as a protein model, the direct electrochemistry of the redox protein was investigated on the PIL-CNTs modified glassy carbon (GC) electrode and excellent direct electrochemical pe... Talanta journals http://www.medworm.com/rss/comments.php?id=3276756 Wed, 17 Feb 2010 08:41:29 +0100 3276756 http://www.medworm.com/index.php?rid=3276755&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%3D20152403%26dopt%3DAbstract This report has described a convenient genotyping method capable of detecting point mutations directly in human genomic DNA based on the combination of ligase chain reaction (LCR) and microbead-enrichment technique. LCR primers, including a biotin-labeled common primer and two fluorescence-labeled allele-specific primers, are designed for two alleles of a mutated site. When genomic DNA carries the mutated site, the common primer and allele-specific primer are ligated to form exponential amplified biotin-labeled fluorescence ligation products. These ligated products are enriched by streptavidin-coated microbeads, and genotypes are identified conveniently according to the fluorescence color of microbeads using fluorescent microscopy. Due to amplification of LCR process and enrichment of micr... Talanta journals http://www.medworm.com/rss/comments.php?id=3276755 Wed, 17 Feb 2010 08:41:26 +0100 3276755 http://www.medworm.com/index.php?rid=3276754&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%3D20152404%26dopt%3DAbstract Authors: de Lima-Neto P, Correia AN, Portela RR, Julião MD, Linhares-Junior GF, de Lima JE The influence of the boron-doping levels in boron-doped diamond film electrodes on the electrochemical response of nitrofurantoin (NFT) and the development of an electroanalytical procedure for NFT determination were investigated. The investigations were carried out using the techniques of cyclic voltammetry and square wave voltammetry on diamond film electrodes with different boron-doping levels (i.e., 5000, 10,000 and 20,000mgL(-1)). The level of boron-doping in the diamond film electrodes influenced the electrochemical reduction of NFT. The appropriate cyclic voltammetric response of NFT was obtained with Britton-Robinson buffer at pH 4 and for diamond films doped with 10,000 and 20,000mg... Talanta journals http://www.medworm.com/rss/comments.php?id=3276754 Wed, 17 Feb 2010 08:41:23 +0100 3276754 http://www.medworm.com/index.php?rid=3276753&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%3D20152405%26dopt%3DAbstract Authors: Hu X, Wang R, Ding Y, Zhang X, Jin W A new electrochemiluminescence (ECL) DNA assay is developed using quantum dots (QDs) as DNA labels. When nanoporous gold leaf (NPGL) electrodes are used, sensitivity of the ECL assay is remarkably increased due to ultra-thin nanopores. In this assay, target DNA (t-DNA) is hybridized with capture DNA (c-DNA) bound on the NPGL electrode, which is fabricated by conjugating amino-modified c-DNA to thioglycolic acid (TGA) modified at the activated NPGL electrode. Following that, amino-modified probe DNA is hybridized with the t-DNA, yielding sandwich hybrids on the NPGL electrode. Then, mercaptopropionic acid-capped CdTe QDs are labeled to the amino group end of the sandwich hybrids. Finally, in the presence of S(2)O(8)(2-) as coreactant, ECL em... Talanta journals http://www.medworm.com/rss/comments.php?id=3276753 Wed, 17 Feb 2010 08:41:21 +0100 3276753 http://www.medworm.com/index.php?rid=3276752&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%3D20152406%26dopt%3DAbstract Authors: Varga Z, Katona R, Stefánka Z, Wallenius M, Mayer K, Nicholl A A novel and simple analytical procedure has been developed for the trace-level determination of lanthanides (rare-earth elements) in uranium-bearing materials by inductively coupled plasma sector-field mass spectrometry (ICP-SFMS). The method involves a selective extraction chromatographic separation of lanthanides using TRU resin followed by ICP-SFMS analysis. The limits of detection of the method proposed is in the low pgg(-1) range, which are approximately two orders of magnitude better than that of without chemical separation. The method was validated by the measurement of reference material and applied for the analysis of uranium ore concentrates (yellow cakes) for nuclear forensic purposes, as a potentia... Talanta journals http://www.medworm.com/rss/comments.php?id=3276752 Wed, 17 Feb 2010 08:41:18 +0100 3276752 http://www.medworm.com/index.php?rid=3276751&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%3D20152407%26dopt%3DAbstract Authors: Mantanus J, Ziémons E, Lebrun P, Rozet E, Klinkenberg R, Streel B, Evrard B, Hubert P A robust near infrared (NIR) method able to quantify the active content of pilot non-coated pharmaceutical pellets was developed. A protocol of calibration was followed, involving 2 operators, independent pilot batches of non-coated pharmaceutical pellets and two different NIR acquisition temperatures. Prediction models based on Partial Least Squares (PLS) regression were then carried out. Afterwards, the NIR method was fully validated for an active content ranging from 80 to 120% of the usual active content using new independent pilot batches to evaluate the adequacy of the method to its final purpose. Conventional criteria such as the R(2), the Root Mean Square Error of Calibration (RM... Talanta journals http://www.medworm.com/rss/comments.php?id=3276751 Wed, 17 Feb 2010 08:41:15 +0100 3276751 http://www.medworm.com/index.php?rid=3276750&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%3D20152408%26dopt%3DAbstract In this study of bacteria associated with the kelp Laminaria digitata, we have isolated 18 epiphytic bacterial strains from several thalli, sequenced their 16S rDNA, built corresponding phylogenetic trees, and characterized them using spectroscopic methods. Molecular taxonomy revealed Gram(+)Actinobacteria and Gram(-)Alphaproteobacteria, Gammaproteobacteria and Bacteroidetes. Twelve marine reference strains (Gram(+)Firmicutes, and Gram(-)Alphaproteobacteria, Gammaproteobacteria and Bacteroidetes) were treated accordingly. Whole-cell MALDI-TOF MS spectral profiles of 29 of the 30 strains were built into a database against which 16 replicate spectra of each strain were compared and categorized into groups. The proton HR-MAS NMR stack plots allowed visual delineation into taxonomic groups acc... Talanta journals http://www.medworm.com/rss/comments.php?id=3276750 Wed, 17 Feb 2010 08:41:12 +0100 3276750 http://www.medworm.com/index.php?rid=3276749&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%3D20152409%26dopt%3DAbstract Authors: Kuligowski J, Quintás G, Garrigues S, de la Guardia M A new background correction method for the on-line coupling of gradient liquid chromatography and Fourier transform infrared spectrometry has been developed. It is based on the use of a point-to-point matching algorithm that compares the absorption spectra of the sample data set with those of a previously recorded reference data set in order to select an appropriate reference spectrum. The spectral range used for the point-to-point comparison is selected with minimal user-interaction, thus facilitating considerably the application of the whole method. The background correction method has been successfully tested on a chromatographic separation of four nitrophenols running acetonitrile (0.08%, v/v TFA):water (0.08%, v/v... Talanta journals http://www.medworm.com/rss/comments.php?id=3276749 Wed, 17 Feb 2010 08:41:10 +0100 3276749 http://www.medworm.com/index.php?rid=3276748&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%3D20152410%26dopt%3DAbstract Authors: Cmelík J, Machát J, Otruba V, Kanický V Vapor generation-inductively coupled plasma-optical emission spectrometry was used for the determination of sulfide in water samples preserved by the addition of a zinc acetate and sodium hydroxide solution. Hydrogen sulfide and acid-volatile sulfides were transformed, by acidification, to a gaseous phase in a vapor generator and subsequently detected by inductively coupled plasma optical emission spectrometry. Compounds interfering with iodometric titration and spectrophotometric determination were examined as potential chemical interferents. The proposed method provides results comparable to iodometric titration in the tested concentration range 0.06-22.0mgL(-1). Limit of detection for the determination of hydrogen sulfi... Talanta journals http://www.medworm.com/rss/comments.php?id=3276748 Wed, 17 Feb 2010 08:41:07 +0100 3276748 http://www.medworm.com/index.php?rid=3276747&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%3D20152411%26dopt%3DAbstract Authors: Núñez L, Turiel E, Martin-Esteban A, Tadeo JL An analytical methodology incorporating a molecularly imprinted solid-phase extraction procedure (MISPE) has been developed for the determination of parabens in environmental solid samples. Four different polymers were prepared combining the use of acetonitrile or toluene as porogen, and 4-vinylpyridine (VP) or methacrylic acid (MAA) as monomer, using benzylparaben (BzP) as a template molecule. Although all the polymers were able to recognize the template in rebinding experiments, the MIP prepared in toluene using MAA showed better performance. This polymer was also capable of recognizing other parabens (methyl, ethyl, isopropyl, propyl, isobutyl, butyl and benzylparaben) allowing to develop an appropriated MISPE procedur... Talanta journals http://www.medworm.com/rss/comments.php?id=3276747 Wed, 17 Feb 2010 08:41:04 +0100 3276747 http://www.medworm.com/index.php?rid=3276746&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%3D20152412%26dopt%3DAbstract Authors: Capella JV, Bonastre A, Ors R, Peris M In this work we propose the implementation of a distributed system based on a Wireless Sensor Network for the control of a chemical analysis system for fresh water. This implementation is presented by describing the nodes that form the distributed system, the communication system by wireless networks, control strategies, and so on. Nitrate, ammonium, and chloride are measured in-line using appropriate ion selective electrodes (ISEs), the results obtained being compared with those provided by the corresponding reference methods. Recovery analyses with ISEs and standard methods, study of interferences, and evaluation of major sensor features have also been carried out. The communication among the nodes that form the distributed system is im... Talanta journals http://www.medworm.com/rss/comments.php?id=3276746 Wed, 17 Feb 2010 08:41:01 +0100 3276746 http://www.medworm.com/index.php?rid=3276745&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%3D20152413%26dopt%3DAbstract This study presents the construction of a rapid and sensitive cellular biosensor test based on the measurement of changes of the cell membrane potential of immobilized cells, according to the working principle of the Bioelectric Recognition Assay (BERA). The cells were immobilized by entrapment in a sodium alginate bead and directly applied in different pesticide dilutions and agricultural samples. The pesticides used were the organophosphate insecticide diazinon and the dithiocarbamate fungicide propineb. Two different cell types, N2a (neuroblastoma) and Vero (fibroblast) were used as the biosensory elements in order to investigate their differential response against the pesticides. In this way, we hoped to increase the selectivity of the assay. Based on the observed patterns of response,... Talanta journals http://www.medworm.com/rss/comments.php?id=3276745 Wed, 17 Feb 2010 08:40:57 +0100 3276745 http://www.medworm.com/index.php?rid=3276744&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%3D20152414%26dopt%3DAbstract Authors: Zejli H, Hidalgo-Hidalgo de Cisneros JL, Naranjo-Rodríguez I, Temsamani KR, Marty JL The Sonogel electrode was immersed in hemin solution to obtain the hemin-Sonogel-modified electrode by cyclic voltammetry (CV). It was applied to detect superoxide radicals produced by xanthine oxidase catalyzed hypoxanthine oxidation. The characterization of hemin-Sonogel was modified by impedance and CV. PMID: 20152414 [PubMed - as supplied by publisher] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=3276744 Wed, 17 Feb 2010 08:40:54 +0100 3276744 http://www.medworm.com/index.php?rid=3276743&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%3D20152415%26dopt%3DAbstract Authors: Toniolo R, Pizzariello A, Susmel S, Dossi N, Bontempelli G A sensitive and fast responding electrochemical sensor is described for the determination of free and total sulphur dioxide in wines and grape juices which prevents interferences coming from ethanol and other natural components. It consists of a cell provided with a porous gold working electrode supported on one face of an ion-exchange membrane, acting as a solid polymer electrolyte (SPE), which allows gaseous electroactive analytes to be detected. This sensor was used as an amperometric detector for a flow injection system in which controlled volumes of headspace equilibrated with samples were injected. This approach was adopted to make also possible the determination of total SO(2), avoiding drawbacks caused by the h... Talanta journals http://www.medworm.com/rss/comments.php?id=3276743 Wed, 17 Feb 2010 08:40:52 +0100 3276743 http://www.medworm.com/index.php?rid=3276742&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%3D20152416%26dopt%3DAbstract Authors: Pillai AK, Jain A, Verma KK Headspace single-drop microextraction has been investigated for the determination of chloride in conjunction with fibre optic-based cuvetteless micro-spectrophotometry which accommodates sample volume of 1muL placed between the two ends of optical fibres. Method has been evolved for the determination of 0.025-4mgL(-1) of chloride involving its oxidation with permanganate in sulphuric acid medium, and reaction of chlorine with 2muL drop of starch-iodide reagent suspended at the tip of microsyringe needle in the headspace of the reaction mixture. The limit of detection was found to be 2.8mugL(-1) of chloride which was better than obtained by existing methods. The method was highly selective and a number of ions which interfered severely in other metho... Talanta journals http://www.medworm.com/rss/comments.php?id=3276742 Wed, 17 Feb 2010 08:40:49 +0100 3276742 http://www.medworm.com/index.php?rid=3276741&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%3D20152417%26dopt%3DAbstract Authors: Talpur MY, Sherazi ST, Mahesar SA, Bhutto AA The aim of present study was to develop a simple method on UV spectrometer for the determination of peroxide value (PV) of the frying oil. The basis of the PV determination was the stoichiometric reaction of triphenylphosphine (TPP) with the hydroperoxides present in frying oil to produce triphenylphosphine oxide (TPPO), which exhibits a readily measurable absorption band at 240nm by ultraviolet region. The PV ranged between 0.15 and 11.66meq. of active oxygen per kilogram of oil as the canola oil was heated from 0 to 12h in the fryer at 180 degrees C. The proposed method was correlated with official AOCS titration method and best correlation coefficient (R(2)=0.99525) was achieved, proving that there is no significant difference in... Talanta journals http://www.medworm.com/rss/comments.php?id=3276741 Wed, 17 Feb 2010 08:40:46 +0100 3276741 http://www.medworm.com/index.php?rid=3276740&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%3D20152418%26dopt%3DAbstract Authors: Rohani T, Taher MA A 4-(2-pyridylazo)-resorcinol (PAR)-modified carbon ceramic electrode (CCE) prepared by the sol-gel technique has been reported for the first time in this paper. By immersing the CCE in aqueous solution of PAR (0.001molL(-1)), after a short period of time, a thin film of PAR was rapidly formed on the surface of the electrode due to its strong adsorption properties. A differential pulse anodic stripping voltammetric (DPASV) method was developed for determination of Ag(I) at the modified carbon ceramic electrode. The analysis procedure consisted of an open circuit accumulation step in a sample solution which was continuously stirred for 12min. This was followed by replacing the medium with a clean solution where the accumulated Ag(I) was reduced for 15s in -0.... Talanta journals http://www.medworm.com/rss/comments.php?id=3276740 Wed, 17 Feb 2010 08:40:44 +0100 3276740 http://www.medworm.com/index.php?rid=3276739&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%3D20152419%26dopt%3DAbstract Authors: Casale M, Sinelli N, Oliveri P, Di Egidio V, Lanteri S The possibility provided by Chemometrics to extract and combine (fusion) information contained in NIR and MIR spectra in order to discriminate monovarietal extra virgin olive oils according to olive cultivar (Casaliva, Leccino, Frantoio) has been investigated. Linear discriminant analysis (LDA) was applied as a classification technique on these multivariate and non-specific spectral data both separately and jointly (NIR and MIR data together). In order to ensure a more appropriate ratio between the number of objects (samples) and number of variables (absorbance at different wavenumbers), LDA was preceded either by feature selection or variable compression. For feature selection, the SELECT algorithm was used while a wavele... Talanta journals http://www.medworm.com/rss/comments.php?id=3276739 Wed, 17 Feb 2010 08:40:41 +0100 3276739 http://www.medworm.com/index.php?rid=3276738&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%3D20152420%26dopt%3DAbstract Authors: Vishnikin AB, Svinarenko TY, Sklenářová H, Solich P, Bazel YR, Andruch V The guanidinium salt of the new heteropolymolybdate 11-molybdobismuthophosphate Gua(6)PBiMo(11)O(40) (11-MBP) was synthesized, characterized and used as a reagent for batch spectrophotometric (SP) and sequential injection determination of ascorbic acid (AsA). When compared to other Keggin's heteropolyanions, the reduction of 11-MBP with AsA is both fast and maximal within a pH range of 1.6-2.0. The stoichiometry of the reaction was determined using molar ratio and continuous variation methods and was shown to be 1:1. The molar absorptivity of the reduced form of 11-MBP was 6.0x10(3)Lmol(-1)cm(-1) at 720nm. The reaction is also specific for AsA. Only cysteine, hydroquinone and hydroxyacids ... Talanta journals http://www.medworm.com/rss/comments.php?id=3276738 Wed, 17 Feb 2010 08:40:38 +0100 3276738 http://www.medworm.com/index.php?rid=3276737&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%3D20152421%26dopt%3DAbstract Authors: Cansever MS, Aktuğlu-Zeybek AC, Erim FB Hereditary tyrosinemia type I is a serious metabolic disorder leading to liver failure. 2-(2-Nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC) is a relatively new drug which is used to prevent the accumulation of toxic metabolites in patients with hereditary tyrosinemia type I. In the present study, we have developed a new, simple, fast, and cost-effective capillary electrophoresis method for the quantitative monitoring of this drug in serum samples. Micellar electrochromatographic separation of NTBC was performed using 20mmol/L phosphate and 40mmol/L sodium dodecylsulfate (SDS) at pH 12 as running electrolyte. Separation of NTBC was achieved in around 4min. Reproducibilities of migration times and corrected peak areas of... Talanta journals http://www.medworm.com/rss/comments.php?id=3276737 Wed, 17 Feb 2010 08:40:35 +0100 3276737 http://www.medworm.com/index.php?rid=3276736&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%3D20152422%26dopt%3DAbstract Authors: Olšovská J, Křesinová Z, Flieger M, Cajthaml T A new ultra high-performance liquid chromatography method with UV detection was examined for detection and separation of polychlorinated biphenyls. This included optimization of separation conditions for two model mixtures containing seven and fifteen most relevant congeners, comparison of three types of reversed phase sub-2-micron particle sized columns and assessment of system suitability under the optimized conditions. Calibration curves determined in the range from 0.5 to 50.0mug/mL exhibited correlation coefficients ranging from 0.997 to 0.999. Lower limits of detection ranged from 0.1 to 0.5ppm. The most efficient Grace C18 column filled with 1.5mum particles was then tested to separate the complex comm... Talanta journals http://www.medworm.com/rss/comments.php?id=3276736 Wed, 17 Feb 2010 08:40:32 +0100 3276736 http://www.medworm.com/index.php?rid=3276735&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%3D20152423%26dopt%3DAbstract Authors: Campillo N, Peñalver R, Hernández-Córdoba M A method based on solid-phase microextraction (SPME) followed by gas chromatography with microwave-induced plasma atomic emission detection for determining dimethylselenide (DMSe) and dimethyldiselenide (DMDSe) in milk and milk by-products is proposed. Parameters affecting the SPME, such as sample volume or mass, ionic strength, adsorption and desorption times and temperatures were optimized in the headspace mode. The matrix effect was evaluated for the different samples studied, concluding that standard additions calibration was required for quantification purposes. The detection limits ranged from 70 to 110pgmL(-1) for DMSe and from 80 to 400pgmL(-1) for DMDSe, depending on the sample under analysis. None of the twen... Talanta journals http://www.medworm.com/rss/comments.php?id=3276735 Wed, 17 Feb 2010 08:40:30 +0100 3276735 http://www.medworm.com/index.php?rid=3276734&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%3D20152424%26dopt%3DAbstract Authors: Holá M, Mikuška P, Hanzlíková R, Kaiser J, Kanický V A study of LA-ICP-MS analysis of pressed powdered tungsten carbide precursors was performed to show the advantages and problems of nanosecond laser ablation of matrix-unified samples. Five samples with different compositions were pressed into pellets both with silver powder as a binder serving to keep the matrix unified, and without any binder. The laser ablation was performed by nanosecond Nd:YAG laser working at 213nm. The particle formation during ablation of both sets of pellets was studied using an optical aerosol spectrometer allowing the measurement of particle concentration in two size ranges (10-250nm and 0.25-17mum) and particle size distribution in the range of 0.25-17mum. Additionally, t... Talanta journals http://www.medworm.com/rss/comments.php?id=3276734 Wed, 17 Feb 2010 08:40:27 +0100 3276734 http://www.medworm.com/index.php?rid=3276733&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%3D20152425%26dopt%3DAbstract Authors: Zheng J, Cheng GF, He PG, Fang YZ An aptamer-based assay for thrombin with high specificity and sensitivity was presented. In the protocol, the aptamer for thrombin was immobilized on magnetic nanoparticle, and its complementary oligonucleotide was labeled with gold nanoparticles, then the aptamer was hybridized with the complementary oligonucleotide to form the duplex structure as a probe, this probe could be used for the specific recognition for thrombin. In the presence of thrombin, the aptamer prefer to form the G-quarter structure with thrombin, resulting in the dissociation of the duplex of the probe and the release of the gold labeled oligonucleotide. Upon this, we were able to detect thrombin through the detection of the electrochemical signal of gold nanoparticles. Th... Talanta journals http://www.medworm.com/rss/comments.php?id=3276733 Wed, 17 Feb 2010 08:40:24 +0100 3276733 http://www.medworm.com/index.php?rid=3276732&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%3D20152426%26dopt%3DAbstract Authors: Zhu L, Pan D, Ding L, Tang F, Zhang Q, Liu Q, Yao S In this paper, a solid-phase extraction (SPE) method based on mixed hemimicelles of cetyltrimethyl ammonium bromide (CTAB) on silica-coated magnetic nanoparticles (MNPs) is developed for extraction and preconcentration of compounds from the biological samples. We selected rhein and emodin which are the major active anthraquinones of rhubarb as model analytes. A high performance liquid chromatography-fluorescence detection (HPLC/FLD) method was developed for the determination of rhein and emodin in urine and serum samples. The main factors influencing the extraction efficiency including the amount of surfactant, the concentration of MNPs, the shaking time and the desorption ability of organic solvents were investigated and opt... Talanta journals http://www.medworm.com/rss/comments.php?id=3276732 Wed, 17 Feb 2010 08:40:21 +0100 3276732 http://www.medworm.com/index.php?rid=3276731&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%3D20152427%26dopt%3DAbstract Authors: Rocha LS, Companys E, Galceran J, Carapuça HM, Pinheiro JP In the present work, the applicability of thin mercury film on a rotating disk electrode (TMF-RDE), to assess the free metal ion concentration by the absence of gradients and Nernstian equilibrium stripping (AGNES), is evaluated. The thickness of the mercury film and several AGNES parameters has been optimized. A nominal 16nm film is chosen due to the higher signal (faradaic current) relative to the value of the noise (capacitive current). Due to the smaller volume to area ratio, the deposition time needed to reach a certain preconcentration factor (Y) is much shorter than in larger electrodes, like the HMDE. The limit of detection (3sigma) for lead(II) is 7.4x10(-9)M and 7.2x10(-8)M for a Y of 5000 (deposition ti... Talanta journals http://www.medworm.com/rss/comments.php?id=3276731 Wed, 17 Feb 2010 08:40:19 +0100 3276731 http://www.medworm.com/index.php?rid=3276730&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%3D20152428%26dopt%3DAbstract Authors: Segovia-Martínez L, Bouzas-Blanco A, Campíns-Falcó P, Seco-Torrecillas A Triethyltin, tributyltin, diphenyltin and triphenyltin were selected as model compounds. The method is based on in situ ethylation and simultaneous headspace-solid-phase microextraction (HS-SPME) and gas chromatographic-mass spectrometry analysis (GC-MS). The extraction procedure was optimized studying some variables such as reaction time, salinity, sample volume and headspace volume. SPME-GC-MS and SPME-GC-FID techniques were compared; quality assurance parameters such as sensitivity, selectivity and precision were established. The proposed procedure showed limits of detection between 0.025 and 1ng/L. The linearity was in the 0.025-5000ng/L range. The precision expressed as relative standa... Talanta journals http://www.medworm.com/rss/comments.php?id=3276730 Wed, 17 Feb 2010 08:40:16 +0100 3276730 http://www.medworm.com/index.php?rid=3276729&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%3D20152429%26dopt%3DAbstract Authors: Kuhn J, Götting C, Kleesiek K Mycophenolic acid (MPA) is an immunosuppressant drug which powerfully inhibits lymphocyte proliferation. Since the early 1990s it has been used to prevent rejection in organ transplantation. The requirement of therapeutic drug monitoring shown in previous studies raises the necessity of acquiring accurate and sensitive methods to measure MPA and its major metabolite mycophenolic acid glucuronide (MPAG). The authors developed a sample cleanup-free, rapid, and highly specific method for simultaneous measurement of MPA and MPAG in human plasma and serum using the novel technology of ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry. MPA- and MPAG-determinations were performed during a 2.0-min run time. Mult... Talanta journals http://www.medworm.com/rss/comments.php?id=3276729 Wed, 17 Feb 2010 08:40:13 +0100 3276729 http://www.medworm.com/index.php?rid=3276728&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%3D20152430%26dopt%3DAbstract Authors: Santos JP, Lozano J, Aleixandre M, Arroyo T, Cabellos JM, Gil M, Horrillo MD An electronic nose (e-nose) based on thin film semiconductor sensors has been developed in order to compare the performance in threshold detection and concentration quantification with a trained human sensory panel in order to demonstrate the use of an e-nose to assess the enologists in an early detection of some chemical compounds in order to prevent wine defects. The panel had 25 members and was trained to detect concentration thresholds of some compounds of interest present in wine. Typical red wine compounds such as whiskeylactone and white wine compounds such as 3-methyl butanol were measured at different concentrations starting from the detection threshold found in literature (in the nanograms t... Talanta journals http://www.medworm.com/rss/comments.php?id=3276728 Wed, 17 Feb 2010 08:40:10 +0100 3276728 http://www.medworm.com/index.php?rid=3276727&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%3D20152431%26dopt%3DAbstract Authors: Zhang Y, Wang W, Li L, Huang Y, Cao J The eggshell membrane (ESM) contains several surface functional groups such as amines, amides and carboxylic groups with potential as SPE adsorbent for the retention of target species of interest. In this paper, the potential use of ESM, a typical biomaterial, as solid-phase extraction (SPE) adsorbent is evaluated for analysis of trace arsenic(V) in environmental water samples in combination with hydride generation atomic fluorescence spectrometry (HG-AFS). In order to obtain the satisfactory recovery of arsenic(V), various parameters including the desorption and enrichment conditions such as pH, the flow rate and the volume of sample solution, the amount of ESM and the content of sodium chloride were systematically optimized and the effec... Talanta journals http://www.medworm.com/rss/comments.php?id=3276727 Wed, 17 Feb 2010 08:40:06 +0100 3276727 http://www.medworm.com/index.php?rid=3276726&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%3D20152432%26dopt%3DAbstract Authors: Yang G, Xu J, Xu L, Chen G, Fu F A microwave-assisted extraction used to extract trace triorganotin from aquatic organisms and a sensitive analytical method for the determination of ultratrace triorganotin (namely trimethyltin, triethyltin, tripropyltin and tributyltin) with capillary electrophoresis-inductively coupled plasma mass spectrometry were firstly described in this study. The extraction method is simple, effective and can be used to extract trace triorganotin in aquatic organisms within several min. The analytical method has a much lower detection limit of 0.2-0.7ngSn/mL for triorganotin compounds, and can be used to determine trace triorganotin in aquatic organisms directly without any derivatization and preconcentration. Using above methods, we have successfully de... Talanta journals http://www.medworm.com/rss/comments.php?id=3276726 Wed, 17 Feb 2010 08:40:03 +0100 3276726 http://www.medworm.com/index.php?rid=3276725&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%3D20152433%26dopt%3DAbstract Authors: Khudaish EA, Farsi AA The self-assembled iodine-adlayer was fabricated at the palladium (Pd) electrode surface throughout a spontaneous oxidative chemisorption of iodide ions contained in an alkaline supporting electrolyte. It enhances the electron transfer kinetics for the oxidation of dopamine (DA) and ascorbic acid (AA) and was important to separate the peak current of both species with a practical potential difference compared with that occurred at the unmodified electrode. The anodic peak currents of both species were linearly increased with their respective concentrations using linear square stripping voltammetry. The activity of the electrode system was further investigated applying chronoamperometry method. The steady-state amperometric signal for the oxidation of DA i... Talanta journals http://www.medworm.com/rss/comments.php?id=3276725 Wed, 17 Feb 2010 08:40:01 +0100 3276725 http://www.medworm.com/index.php?rid=3276724&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%3D20152434%26dopt%3DAbstract Authors: Hashemi P, Raeisi F, Ghiasvand AR, Rahimi A A reversed-phase dispersive liquid-liquid microextraction (RP-DLLME) method was developed for the preconcentration and direct HPLC determination of oleuropein in olive's processing wastewater (OPW) and olive leaves extracts. In conventional DLLME, the sedimented phase is a micro-drop of a chlorinated organic solvent that is not compatible with RP-HPLC. Therefore, solvent evaporation and reconstitution with an appropriate solvent is often required. In RP-DLLME, this problem was overcome by overturning the solvent polarity in the ordinary DLLME and replacing the organic solvent with water. A central composite chemometrics design was used for multivariate optimization of the effects of five different parameters influencing the extractio... Talanta journals http://www.medworm.com/rss/comments.php?id=3276724 Wed, 17 Feb 2010 08:39:58 +0100 3276724 http://www.medworm.com/index.php?rid=3276723&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%3D20152435%26dopt%3DAbstract Authors: Maule C, Gonçalves H, Mendonça C, Sampaio P, Esteves da Silva JC, Jorge P CdTe quantum dots (QDs), capped with mercaptopropionic acid (MPA), were synthesized and the variation of their fluorescence properties (steady state and lifetime) with pH was assessed in solution and when immobilized in a sol-gel host. Three different sizes of CdTe QDs with excited state lifetimes ranging from 42 to 48ns and with emission maximum at 540nm (QD(540)), 580nm (QD(580)) and 625nm (QD(625)) were selected. The solution pH affects the maximum emission wavelength (shifts to higher wavelengths of 23, 24 and 27nm for QD(540), QD(580) and QD(625), respectively), the excited state lifetime and the fluorescence intensity in a reversible way. Linearization of the maximum emission wavelength v... Talanta journals http://www.medworm.com/rss/comments.php?id=3276723 Wed, 17 Feb 2010 08:39:55 +0100 3276723 http://www.medworm.com/index.php?rid=3276722&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%3D20152436%26dopt%3DAbstract Authors: Li CF, Du LM, Wu WY, Sheng AZ The supramolecular interaction of a homologous series of cucurbit[n]uril (CB[n], n=5, 6, 7, 8) hosts and coptisine (COP) was studied by spectrofluorimetry. All of the CB[n]s were found to react with COP to form 1:1 host-guest stable complexes and the fluorescence intensity of the complexes was greatly enhanced. The apparent association constants of the complexes were 1.44x10(4), 1.28x10(4), 1.86x10(4) and 1.26x10(4)Lmol(-1) for CB[5], CB[6], CB[7] and CB[8], respectively. In addition, CB[5] and CB[7] exhibited a higher fluorescence signal than CB[6] and CB[8]. The fluorescence intensity of the complex with CB[7] was enhanced 70-fold compared to that of the studied drug itself. Based on the significant enhancement of fluorescence intensity of supra... Talanta journals http://www.medworm.com/rss/comments.php?id=3276722 Wed, 17 Feb 2010 08:39:53 +0100 3276722 http://www.medworm.com/index.php?rid=3276721&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%3D20152437%26dopt%3DAbstract Authors: Zuliani T, Lespes G, Milačič R, Sčančar J The toxicity and bioaccumulation of organotin compounds (OTCs) led to the development of sensitive and selective analytical methods for their determination. In the past much attention was assigned to the study of OTCs in biological samples, water and sediments, coming mostly from marine environment. Little information about OTCs pollution of terrestrial ecosystems is available. In order to optimise the extraction method for simultaneous determination of butyl-, phenyl- and octyltin compounds in sewage sludge five different extractants (tetramethylammonium hydroxide, HCl in methanol, glacial acetic acid, mixture of acetic acid and methanol (3:1), and mixture of acetic acid, methanol and water (1:1:1)), the presen... Talanta journals http://www.medworm.com/rss/comments.php?id=3276721 Wed, 17 Feb 2010 08:39:50 +0100 3276721 http://www.medworm.com/index.php?rid=3276720&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%3D20152438%26dopt%3DAbstract Authors: Chen XT, Xiang Y, Tong AJ A novel fluorescence turn-on detection method of human serum albumin (HSA) and bovine serum albumin (BSA) in aqueous solution is investigated using 2,4-dihydroxyl-3-iodo salicylaldehyde azine (DISA). Upon the addition of DISA to HSA/BSA solution, a fluorescence turn-on effect at 529nm can be observed with a large stokes shift of approximately 129nm based on hydrophobic binding-mode between protein and dye. Under the optimal condition, the linear ranges of fluorescence intensity for HSA and BSA are 0.1-30mugmL(-1) with the relative correlation coefficient of R(2)=0.991 (n=10) and 0.3-50mugmL(-1) with R(2)=0.997 (n=10); and the detection limits for HSA and BSA based on IUPAC (C(DL)=3S(b)/m) are 20ngmL(-1) and 50ngmL(-1), respectively. PMID: 20152438... Talanta journals http://www.medworm.com/rss/comments.php?id=3276720 Wed, 17 Feb 2010 08:39:47 +0100 3276720 http://www.medworm.com/index.php?rid=3276719&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%3D20152439%26dopt%3DAbstract Authors: Wang Y, Liu Z, Yao G, Zhu P, Hu X, Xu Q, Yang C This work exploited a sequential injection lab-on-valve (LOV) system for the determination of cadmium by anodic stripping voltammetry (ASV). A miniaturized electrochemical flow cell (EFC) was fabricated in LOV, in which a nafion coated bismuth film electrode was used as working electrode. The cadmium was electrodeposited on the electrode surface in bismuth solution, and measured with the subsequential stripping scan. Under optimal conditions, the proposed system responded linearly to cadmium concentrations in a range 2.0-100.0mugL(-1). The detection limit of this method was found to be 0.88mugL(-1). By loading a sample volume of 800muL, a sampling frequency of 22 determinations h(-1) was achieved. The repeatability expressed as r... Talanta journals http://www.medworm.com/rss/comments.php?id=3276719 Wed, 17 Feb 2010 08:39:42 +0100 3276719 http://www.medworm.com/index.php?rid=3276718&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%3D20152440%26dopt%3DAbstract This study presents a high-performance ratiometric pH optode based on the fluorophore 6,8-dihydroxypyrene-1,3-disulfonic acid (DHPDS). The two pH-sensitive terminal hydroxy groups of DHPDS facilitated dual excitation/dual emission (F(1): lambda(1,ex)=420nm, lambda(1,em)=462nm; F(2): lambda(2,ex)=470nm, lambda(2,em)=498nm) properties for ratiometric (R(F1,F2)=F(1)/F(2)) normalization of sensor signal. The sensor demonstrated an exponentially decreasing ratiometric response with increasing pH, with a linear correlation (R(2)=0.9936) between (10)log(R(F1,F2)) and pH within the pH interval 6-9. Precision determined as the IUPAC pooled standard deviation for the pH values 6.00, 7.01 and 9.01, was 0.0057 pH units for the fluorosensor and 0.0054 for a commercially available pH electrode used for ... Talanta journals http://www.medworm.com/rss/comments.php?id=3276718 Wed, 17 Feb 2010 08:39:39 +0100 3276718 http://www.medworm.com/index.php?rid=3276717&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%3D20152441%26dopt%3DAbstract Authors: Nováková L, Spáčil Z, Seifrtová M, Opletal L, Solich P Twenty nine phenolic compounds comprising nine phenolic acids, sixteen flavonoids (including eight tea catechins, glycosides and aglycones), four coumarins plus caffeine were analysed within 20min using ultra high performance liquid chromatography (UHPLC) with PDA detection. UHPLC system was equipped with C18 analytical column (100mmx2.1mm, 1.7mum), utilising 0.1% formic acid and methanol mobile phase in the gradient elution mode. The developed method was tested for the system suitability: resolution, asymmetry factor, peak capacity, retention time repeatability and peak area repeatability. The method was fully validated in the terms of linearity (r(2)>0.9990 for all 30 compounds), range (typic... Talanta journals http://www.medworm.com/rss/comments.php?id=3276717 Wed, 17 Feb 2010 08:39:36 +0100 3276717 http://www.medworm.com/index.php?rid=3276716&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%3D20152442%26dopt%3DAbstract Authors: Catterall K, Robertson D, Teasdale PR, Welsh DT, John R A number of recent studies have utilised ferricyanide as a respiratory mediator for microbial-based assays for determining water quality parameters such as biochemical oxygen demand (BOD) and toxicity. The majority of assays published to date obtain a result by determining the difference in ferrocyanide accumulation between a test sample and one or more control samples. However, a validation of the relationship between ferrocyanide accumulation and standard measures of cell density or viability has not yet been performed. To this end, a rapid microbially catalysed ferricyanide-mediated respiration (FM-RES) assay was compared with standard plate count (SPC) and spectrophotometer (OD(600)) measurements on a growing batch cu... Talanta journals http://www.medworm.com/rss/comments.php?id=3276716 Wed, 17 Feb 2010 08:39:33 +0100 3276716 http://www.medworm.com/index.php?rid=3276715&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%3D20152443%26dopt%3DAbstract Authors: Arévalo FJ, Messina GA, Molina PG, Zón MA, Raba J, Fernández H Progesterone (P4) is a steroidal hormone with a vital role in the maintenance of human and animal health. This paper describes the development of an immunosensor coupled to glassy carbon (GC) electrode and integrated to a microfluidic system to quantify P4 from bovine serum samples in a fast and sensitive way. The serum samples spiked with a given P4 concentration and a given P4 concentration bound to horseradish peroxide (HPR) were simultaneously added and, therefore, they competed immunologically with sheep monoclonal anti-P4 antibodies that were immobilized at a rotating disk. HRP in the presence of hydrogen peroxide (H(2)O(2)) catalyzes the chatecol (H(2)Q) oxidation to benzoquinone (Q). Its reve... Talanta journals http://www.medworm.com/rss/comments.php?id=3276715 Wed, 17 Feb 2010 08:39:30 +0100 3276715 http://www.medworm.com/index.php?rid=3276714&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%3D20152444%26dopt%3DAbstract Authors: Collins CJ, Lyons C, Strutwolf J, Arrigan DW In this work, the effect of the serum protein, bovine serum albumin (BSA), on the detection of propranolol in artificial serum by ion-transfer voltammetry at an array of micro-interfaces between two immiscible electrolyte solutions (muITIES) is presented. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and differential pulse stripping voltammetry (DPSV) were examined for the detection of low concentrations of propranolol. Both CV and DPV had an interference effect from BSA, manifested as lower currents in the presence of the protein. DPSV proved to be the most effective technique, enabling the detection of 0.05muM propranolol in the presence of BSA. The DPSV method employed a preconditioning step as well as a preconce... Talanta journals http://www.medworm.com/rss/comments.php?id=3276714 Wed, 17 Feb 2010 08:39:28 +0100 3276714 http://www.medworm.com/index.php?rid=3276713&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%3D20152445%26dopt%3DAbstract Authors: Santos KD, Braga OC, Vieira IC, Spinelli A A boron-doped diamond (BDD) electrode was used for the electroanalytical determination of estriol hormone in a pharmaceutical product and a urine sample taken during pregnancy by square-wave voltammetry. The optimized experimental conditions were: (1) a supporting electrolyte solution of NaOH at a pH of 12.0, and (2) a frequency of 20Hz, a pulse height of 30mV and a scan increment of 2mV (for the square-wave parameters). The analytical curve was linear in the concentration range of 2.0x10(-7) to 2.0x10(-5)molL(-1) (r=0.9994), with a detection limit of 1.7x10(-7)molL(-1) and quantification limit of 8.5x10(-7)molL(-1). Recoveries of estriol were in the range of 98.6-101.0%, for the pharmaceutical sample, and 100.2-103.4% for the urine s... Talanta journals http://www.medworm.com/rss/comments.php?id=3276713 Wed, 17 Feb 2010 08:39:25 +0100 3276713 http://www.medworm.com/index.php?rid=3276712&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%3D20152446%26dopt%3DAbstract Authors: Wagieh NE, Hegazy MA, Abdelkawy M, Abdelaleem EA Simple, accurate, sensitive and validated UV spectrophotometric, chemometric and HPTLC-densitometric methods were developed for determination of oxybutynin hydrochloride (OX) in presence of its degradation product and additives in its pharmaceutical formulations. Method A is the first derivative of ratio spectra (DD(1)) which allows the determination of OX in presence of its degradate in pure form and tablets by measuring the peaks amplitude at 216nm. Method B and C are principal component regression (PCR) and partial least-squares (PLS) for determination of OX in presence of its degradate in pure form, tablets and syrup. While, the developed high performance thin layer chromatography HPTLC-densitometric method was based on the ... Talanta journals http://www.medworm.com/rss/comments.php?id=3276712 Wed, 17 Feb 2010 08:39:22 +0100 3276712 http://www.medworm.com/index.php?rid=3276711&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%3D20152447%26dopt%3DAbstract Authors: Baby TT, Ramaprabhu S A new type of amperometric glucose biosensor based on silicon dioxide coated magnetic nanoparticle decorated multiwalled carbon nanotubes (Fe(3)O(4)@SiO(2)/MWNTs) on a glassy carbon electrode (GCE) has been developed. MWNTs have been synthesized by catalytic chemical vapour decomposition (CCVD) of acetylene over rare earth (RE) based AB(3) alloy hydride catalyst. The as-grown MWNTs have been purified and further functionlized. Functionalized MWNTs have been decorated with magnetic Fe(3)O(4) nanoparticles which have been uniformly coated with biocompatible SiO(2) using a simple chemical reduction method. The characterization of magnetic nanoparticle modified MWNTs have been done by X-ray diffraction (XRD), Fourier transform infra red spectroscopy (FT-IR), ... Talanta journals http://www.medworm.com/rss/comments.php?id=3276711 Wed, 17 Feb 2010 08:39:20 +0100 3276711 http://www.medworm.com/index.php?rid=3276710&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%3D20152448%26dopt%3DAbstract Authors: Shamsipur M, Sadeghi M, Alizadeh K, Bencini A, Valtancoli B, Garau A, Lippolis V A novel fluorescence chemical sensor for the highly sensitive and selective determination of Pb(2+) ions in aqueous solutions is described. The preliminary potentiometric and spectrofluorimetric complexation studies in solution revealed that the lipophilic ligand 5,8-bis((5'-chloro-8'-hydroxy-7'-quinolinyl)methyl)-2,11-dithia-5,8-diaza-2,6-pyridinophane (L2) forms a highly stable and selective [PbL2](2+) and [Pb(L2)(2)](2+) complexes which results in a strong fluorescence quenching of the ligand. Thus, a novel fluorescence Pb(2+) sensing system was prepared by incorporating L2 as a neutral lead-selective fluoroionophore in the plasticized PVC membrane containing tetrakis(p-chlorophenyl) borate as ... Talanta journals http://www.medworm.com/rss/comments.php?id=3276710 Wed, 17 Feb 2010 08:39:17 +0100 3276710 http://www.medworm.com/index.php?rid=3276709&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%3D20152449%26dopt%3DAbstract Authors: Martinis EM, Bertón P, Altamirano JC, Hakala U, Wuilloud RG A highly efficient single-drop microextraction (SDME) procedure using a low-cost room temperature ionic liquid (RTIL), i.e., tetradecyl(trihexyl)phosphonium chloride (CYPHOS((R)) IL 101), for Pb determination at trace levels in real water samples was developed. Lead was chelated with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) reagent and extracted into a 4muL microdrop of CYPHOS((R)) IL 101. The RTIL drop was directly injected into the graphite furnace of the electrothermal atomic absorption spectrometer (ETAAS). Under optimal microextraction conditions, a preconcentration factor of 32 was achieved with only 1.5mL of sample resulting in a phase-volume ratio of 375. The limit of detection (LOD) obt... Talanta journals http://www.medworm.com/rss/comments.php?id=3276709 Wed, 17 Feb 2010 08:39:14 +0100 3276709 http://www.medworm.com/index.php?rid=3276708&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%3D20152450%26dopt%3DAbstract This study is the first precedent of the use of SPMDs for the simultaneous sampling of a wide number of VOCs. The use of SPMDs is a simple and low cost alternative to ordinary sampling devices such as Radiello((R)) diffusive samplers or badge-type solid-phase supports. PMID: 20152450 [PubMed - as supplied by publisher] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=3276708 Wed, 17 Feb 2010 08:39:10 +0100 3276708 http://www.medworm.com/index.php?rid=3276707&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%3D20152451%26dopt%3DAbstract Authors: Tsogas GZ, Giokas DL, Vlessidis AG In this work, a rapid assay of water hardness is presented based on the formation of a coacervate phase made up of multilamellar vesicles and close bilayers produced upon the reaction of alkaline earth metals with a carboxylate anionic surfactant in the presence of a co-surfactant (methanol). The procedure exploits the light scattering abilities of the coacervate phase which can be logarithmically linked to total hardness as CaCO(3) equivalents via spectrophotometric detection at 350nm. The method, abbreviated as HALC, stemming from hardness by alkaline earth metal coacervation, is straightforwardly applicable overcoming the requirement for regulation of the experimental parameters involved in the determination procedure. In total, 28 water s... Talanta journals http://www.medworm.com/rss/comments.php?id=3276707 Wed, 17 Feb 2010 08:39:07 +0100 3276707 http://www.medworm.com/index.php?rid=3276706&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%3D20152452%26dopt%3DAbstract Authors: Yiantzi E, Psillakis E, Tyrovola K, Kalogerakis N A new and fast equilibrium-based solvent microextraction technique termed vortex-assisted liquid-liquid microextraction (VALLME) has been developed and used for the trace analysis of octylphenol, nonylphenol and bisphenol-A in water and wastewater samples. According to VALLME, dispersion of microvolumes of a low density extractant organic solvent into the aqueous sample is achieved by using for the first time vortex mixing, a mild emulsification procedure. The fine droplets formed could extract target analytes towards equilibrium faster because of the shorter diffusion distance and larger specific surface area. Upon centrifugation the floating extractant acceptor phase restored its initial single microdrop shape and was used fo... Talanta journals http://www.medworm.com/rss/comments.php?id=3276706 Wed, 17 Feb 2010 08:39:04 +0100 3276706 http://www.medworm.com/index.php?rid=3276705&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%3D20152453%26dopt%3DAbstract In this study, the influence of solvent grade quality on the response of a DNA-binding AhR mediated assay used for screening dioxins has been investigated. Our results demonstrated a very critical impact of this parameter with both strong agonistic and antagonistic effects observed for any tested solvent lot. A small silver nitrate silica column removed partly these interfering compounds and then can be recommended as final purification step. Some preferable grades can be identified and selected in order to guarantee the best possible performances. However, it appears necessary to test every new lot, even if a grade appeared previously compliant. PMID: 20152453 [PubMed - as supplied by publisher] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=3276705 Wed, 17 Feb 2010 08:39:02 +0100 3276705 http://www.medworm.com/index.php?rid=3276704&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%3D20152454%26dopt%3DAbstract Authors: Kollander B, Andersson M, Pettersson J A fast method for direct multi-element analysis of non-digested biological samples is presented. The only sample preparation needed is 1min homogenization with a Polytron mixer in a small volume of neutral phosphate buffer saline solution (PBS). The total time for analysis (sample preparation and measurement) is 4min only. This "mix and measure" method can handle large sample loads of biological samples and thus minimize dilution of trace elements. For example 100% whole blood was introduced without any clogging of the introduction system or extinguishing of the plasma. In 70% (v/v) whole blood reference material 14 of 16 analytes were quantified within +/-10% (Al, B, Ba, Ca, Cu, Fe, Mg, Mn, P, Pb, S, Sr, Ti and Zn) and two semi-quantifie... Talanta journals http://www.medworm.com/rss/comments.php?id=3276704 Wed, 17 Feb 2010 08:38:59 +0100 3276704 http://www.medworm.com/index.php?rid=3276703&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%3D20152455%26dopt%3DAbstract Authors: Rios JJ, Morales A, Márquez-Ruiz G A solvent-free analytical approach based on headspace solid-phase microextraction (SPME) of oil matrices heated at high temperatures coupled to gas chromatography with mass spectrometry detector (GC-ion trap) has been developed for the determination of phthalic acid esters (PAEs) in oil matrices without sample manipulation. For this study, three fibers, i.e., 85mum-polyacrylate (PA), 50/30mum-divinylbenzene-carboxen-polydimethylsiloxane (DVB/CAR/PDMS) and 100mum-polydimethylsiloxane (PDMS) were tested. Variables affecting the SPME headspace composition such as incubation sample temperature, sample incubation time and fiber exposition time were optimized. The optimal values found were 250 degrees C for sample incubation temperature and 30... Talanta journals http://www.medworm.com/rss/comments.php?id=3276703 Wed, 17 Feb 2010 08:38:56 +0100 3276703 http://www.medworm.com/index.php?rid=3276702&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%3D20152456%26dopt%3DAbstract Authors: Prieto-Blanco MC, Iglesias MP, López-Mahía P, Lorenzo SM, Rodríguez DP Simultaneous analysis of 24 carbonyl compounds (alkanals, unsaturated, dicarbonylic and aromatic aldehydes and ketones) derivatized with 2,4-dinitrophenylhydrazine and 16 polycyclic aromatic hydrocarbons (PAHs) using a photodiode-array (PDA) and a fluorescence (FL) detector in series is proposed. The separation is carried out with a reversed-phase column and gradient elution using four solvents (acetonitrile, water, tetrahydrofuran and methanol) in less than 35min. Several critical pairs of carbonyl compounds with 3 and 4 carbon atoms and different functional groups, isomers of tolualdehyde, aromatic and aliphatic aldehydes were conditional on the gradient elution. Common pre-treatment for tw... Talanta journals http://www.medworm.com/rss/comments.php?id=3276702 Wed, 17 Feb 2010 08:38:54 +0100 3276702 http://www.medworm.com/index.php?rid=3276701&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%3D20152457%26dopt%3DAbstract Authors: Mao J, He Q, Liu W An "off-on" rhodamine-based fluorescence probe for the selective signaling of Fe(III) has been designed exploiting the guest-induced structure transform mechanism. This system shows a sharp Fe(III)-selective fluorescence enhancement response in 100% aqueous system under physiological pH value and possesses high selectivity against the background of environmentally and biologically relevant metal ions including Al(III), Cd(II), Fe(II), Co(II), Cu(II), Ni(II), Zn(II), Mg(II), Ba(II), Pb(II), Na(I), and K(I). Under optimum conditions, the fluorescence intensity enhancement of this system is linearly proportional to Fe(III) concentration from 6.0x10(-8) to 7.2x10(-6)molL(-1) with a detection limit of 1.4x10(-8)molL(-1). PMID: 20152457 [PubMed - as supplied b... Talanta journals http://www.medworm.com/rss/comments.php?id=3276701 Wed, 17 Feb 2010 08:38:51 +0100 3276701 http://www.medworm.com/index.php?rid=3276700&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%3D20152458%26dopt%3DAbstract Authors: Hu Y, Wang Y, Chen X, Hu Y, Li G The combination of molecular imprinting and solid-phase microextraction (SPME) technique provides a powerful sample preparation tool in terms of selectivity, simplicity, and flexibility. This paper reports a novel molecularly imprinted polymer (MIP) coated SPME fiber with 17beta-estradiol as template by improved multiple co-polymerization method. The obtained fiber exhibits excellent characteristics such as high porosity, good thermal and chemical stability. Extraction performance shows that the MIP-coated fiber has stronger affinity to the template molecule as compared with the commercial SPME fibers and the control polymer-coated fiber without addition of template. Owing to the shape and structural compatibility, the obtained fiber also demon... Talanta journals http://www.medworm.com/rss/comments.php?id=3276700 Wed, 17 Feb 2010 08:38:48 +0100 3276700 http://www.medworm.com/index.php?rid=3276699&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%3D20152459%26dopt%3DAbstract In this study we firstly report a new electrolytic cold vapor generation system for mercury determination on Pt/Ti cathode in the presence of organic acid catholyte. Comparing with the traditional inorganic acid, formic acid increased the signal intensity of Hg vapor from electrolytic generation on Pt cathode and reduced the impact of cathode erosion on the stability of signal intensity. Moreover, formic acid has better interference tolerance. The introduction location for carrier gas is probably the most important factor that influences the signal intensity of Hg from electrolytic vapor generation. The effects of the electrolytic conditions and interference ions on the ECVG have been studied. Under the optimized conditions, the detection limit (3sigma) of Hg (II) in aqueous solutions is 1... Talanta journals http://www.medworm.com/rss/comments.php?id=3276699 Wed, 17 Feb 2010 08:38:45 +0100 3276699 http://www.medworm.com/index.php?rid=3276698&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%3D20152460%26dopt%3DAbstract Authors: Lin L, Chen J, Lin Q, Chen W, Chen J, Yao H, Liu A, Lin X, Chen Y A novel electrochemical biosensor is described for detection of breakpoint cluster region gene and a cellular abl (BCR/ABL) fusion gene in chronic myelogenous leukemia (CML) by using thiolated-hairpin locked nucleic acids (LNA) as the capture probe. The hairpin LNA probe was immobilized on the nanogold (NG)/poly-eriochrome black T (EBT) film-modified glassy carbon electrode (GCE). The immobilized LNA probe could selectively hybridize with its target DNA on LNA/NG/EBT/GCE surface. The immobilization and hybridization of the LNA probe were characterized with cyclic voltammetry and electrochemical impedance spectroscopy. The hybridization of the immobilized LNA probe with the target DNA was detected by differential... Talanta journals http://www.medworm.com/rss/comments.php?id=3276698 Wed, 17 Feb 2010 08:38:43 +0100 3276698 http://www.medworm.com/index.php?rid=3276697&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%3D20152461%26dopt%3DAbstract Authors: Frankowski M, Zioła-Frankowska A, Siepak J Speciation analysis of aluminium in the presented system of HPLC-FAAS hyphenated technique lasts 4min. Using the bifunctional column in model analysis and using the calculation methods for modelling using the Mineql program enabled the authors to presume that particular forms will be subjected to elution in the following order: (1) AlF(2)(+) and AlF(4)(-), (2) AlF(2+) and AlF(3)(0) and (3) Al(3+). Based on the obtained results for model solutions, the presented method enables the determination of aluminium fluoride complexes and Al(3+) speciation form. The study compares the tendency of occurrence variability of aluminium fluoride complexes and Al(3+) form, determined based on the results obtained using the HPLC-FAAS hyphenated ... Talanta journals http://www.medworm.com/rss/comments.php?id=3276697 Wed, 17 Feb 2010 08:38:40 +0100 3276697 http://www.medworm.com/index.php?rid=3276696&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%3D20152462%26dopt%3DAbstract Authors: Sahan S, Saçmacı S, Sahin U, Ulgen A, Kartal S An on-line preconcentration procedure for the determination of bismuth by flame atomic absorption spectrometry (FAAS) has been described. Lewatit TP-207 chelating resin, including iminodiacetate group, packed in a minicolumn was used as adsorbent material. Bi(III) was sorbed on the chelating resin, from which it could be eluted with 3molL(-1) HNO(3) and then introduced directly to the nebulizer-burner system of FAAS. Best preconcentration conditions were established by testing different resin quantities, acidity of sample, types of eluent, sample and eluent solution volumes, adsorption and elution flow rates, and effect of interfering ions. The detection limit of the method was 2.75mugL(-1) while the relative standard d... Talanta journals http://www.medworm.com/rss/comments.php?id=3276696 Wed, 17 Feb 2010 08:38:37 +0100 3276696 http://www.medworm.com/index.php?rid=3276695&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%3D20152463%26dopt%3DAbstract Authors: Ammam M, Keita B, Nadjo L, Fransaer J A nitrite sensor based on immobilized Dawson-type tungstophosphate alpha-K(7)[H(4)PW(18)O(62)].18H(2)O (PW(18)) in multilayers of charged polyelectrolyte poly(allylamine hydrochloride) (PAH) on a glassy carbon electrode is described. A nitrite sensor manufactured with 10 layers has a sensitivity of approximately 4nA/muM nitrite, fast response time (<6s), low detection limit ( approximately 0.1muM), high selectivity towards endogenous interferences such as nitrate and molecular oxygen, a linear range from 0.1muM to at least 20mM nitrite and was stable for at least 2 months. In addition, such nitrite sensors can operate in a pH range from 1 to 9, and the sensitivity can be increased by increasing the number of layers at the expense of inc... Talanta journals http://www.medworm.com/rss/comments.php?id=3276695 Wed, 17 Feb 2010 08:38:34 +0100 3276695 http://www.medworm.com/index.php?rid=3276694&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%3D20152464%26dopt%3DAbstract Authors: Mannina L, Marini F, Gobbino M, Sobolev AP, Capitani D An NMR and chemometric analytical approach to classify extra virgin olive oils according to their geographical origin was developed within the European TRACE project (FP6-2003-FOOD-2-A, contract number: 0060942). Olive oils (896 samples) of three consecutive harvesting years (2005, 2006, and 2007) coming from Mediterranean areas were analyzed by (1)H NMR spectroscopy. Olive oil samples from Liguria, an Italian region, were chosen as a case study and PLS-DA and SIMCA modeling analyses were used to build up statistical models both to discriminate between Ligurian and non-Ligurian olive oils and to define the Ligurian olive oil class to confirm the declared provenience. PMID: 20152464 [PubMed - as supplied by publisher] (... Talanta journals http://www.medworm.com/rss/comments.php?id=3276694 Wed, 17 Feb 2010 08:38:31 +0100 3276694 http://www.medworm.com/index.php?rid=3276693&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%3D20152465%26dopt%3DAbstract Authors: Moreno M, Arribas AS, Bermejo E, Chicharro M, Zapardiel A, Rodríguez MC, Jalit Y, Rivas GA This work reports on the performance of carbon nanotube modified screen-printed electrodes (SPE-MWCNT) for the selective determination of dopamine (DA) in the presence of ascorbic acid (AA) by adsorptive stripping voltammetry (AdSV). Several operating conditions and parameters were examined including the electrochemical pre-treatment and the previous AA interaction and DA accumulation in the presence AA at physiological conditions. Under the chosen conditions, DA peak current of differential pulse voltammograms increases linearly with DA concentration in the range of 5.0x10(-8) to 1.0x10(-6)molL(-1) with a limit of detection of 1.5x10(-8)molL(-1) in connection with 600s accumulation... Talanta journals http://www.medworm.com/rss/comments.php?id=3276693 Wed, 17 Feb 2010 08:38:28 +0100 3276693 http://www.medworm.com/index.php?rid=3276692&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%3D20152466%26dopt%3DAbstract Authors: Polonschii C, David S, Tombelli S, Mascini M, Gheorghiu M A novel low-cost platform to assess biomolecular interactions was investigated using surface plasmon resonance and an aptamer-based assay for thrombin detection. Gold SPR surface functionalized with a carboxylated cross-linked BSA film (cBSA) and commercially available carboxymethylated dextran chip (CM5) were used as immobilization platforms for the thrombin binding aptamer. The high end commercial instrument Biacore 3000 and a custom made FIA set-up involving TI Spreeta sensor (TSPR2K23) were used to assess different concentrations of thrombin within the range 0.1-150nM both in buffer and in a complex matrix (plasma) using the obtained aptasensors. Based on data derived from both CM5 and cBSA platforms, the cBSA aptas... Talanta journals http://www.medworm.com/rss/comments.php?id=3276692 Wed, 17 Feb 2010 08:38:25 +0100 3276692 http://www.medworm.com/index.php?rid=3276691&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%3D20152467%26dopt%3DAbstract Authors: Agiomyrgianaki A, Petrakis PV, Dais P NMR spectroscopy was employed for the detection of adulteration of refined olive oil with refined hazelnut oil. Fatty acids and iodine number were determined by (1)H NMR, whereas (31)P NMR was used for the quantification of minor compounds including phenolic compounds, diacylglycerols, sterols, and free fatty acids (free acidity). Classification of the refined oils based on their fatty acids content and the concentration of their minor compounds was achieved by using the forward stepwise canonical discriminant analysis (CDA) and the classification binary trees (CBTs). Both methods provided good discrimination between the refined hazelnut and olive oils. Different admixtures of refined olive oils with refined hazelnut oils were prepared and... Talanta journals http://www.medworm.com/rss/comments.php?id=3276691 Wed, 17 Feb 2010 08:38:23 +0100 3276691 http://www.medworm.com/index.php?rid=3276690&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%3D20152468%26dopt%3DAbstract Authors: Liang GX, Liu HY, Zhang JR, Zhu JJ The near-infrared (NIR)-emitting CdSeTe alloyed quantum dots (AQdots) that capped with l-cysteine were applied for ultrasensitive Cu(2+) sensing. The sensing approach was based on the fluorescence of the AQdots selectively quenched in the presence of Cu(2+). Experimental results showed a low interference response towards other metal ions. The possible quenching mechanism was discussed on the basis of the binding between l-cysteine and the metal ions. In addition, biomolecules have low effect on the fluorescence due to the minimized interferences in NIR region. The response of the NIR optical sensor was linearly proportional to the concentration of Cu(2+) ranging from 2x10(-8) to 2x10(-6)molL(-1). Furthermore, it has been successfully applied ... Talanta journals http://www.medworm.com/rss/comments.php?id=3276690 Wed, 17 Feb 2010 08:38:20 +0100 3276690 http://www.medworm.com/index.php?rid=3276689&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%3D20152469%26dopt%3DAbstract Authors: Sun W, Qin P, Zhao R, Jiao K In this paper a carbon ionic liquid electrode (CILE) was fabricated by using ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM]EtOSO(3)) as modifier and further gold nanoparticles were in situ electrodeposited on the surface of CILE. The fabricated Au/CILE was used as a new platform for the immobilization of hemoglobin (Hb) with the help of a Nafion film. Electrochemical experimental results indicated that direct electron transfer of Hb was realized on the surface of Au/CILE with a pair of well-defined quasi-reversible redox peaks appeared. The formal peak potential (E(0)') was obtained as -0.210V (vs. SCE) in pH 7.0 phosphate buffer solution (PBS), which was the characteristic of Hb heme Fe(III)/Fe(II) redox couple. The fabricated Nafio... Talanta journals http://www.medworm.com/rss/comments.php?id=3276689 Wed, 17 Feb 2010 08:38:17 +0100 3276689 http://www.medworm.com/index.php?rid=3276688&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%3D20152470%26dopt%3DAbstract Authors: Tang X, Liu Y, Hou H, You T A novel and simple method for the direct and quantitative determination of L-tryptophan (Trp), L-tyrosine (Tyr) and L-cysteine (Cys) was proposed in this work. Carbon nanofibers (CNFs), made by electrospinning technique, were used to modify carbon paste electrode (CPE) without any treatment to study the electrochemical behaviors of the three amino acids using cyclic voltammetry (CV) and constant potential amperometric method. The results demonstrated that the CNFs modified carbon paste electrode (CNF-CPE) exhibited high electrocatalytic activity and good analytical performance towards the oxidation of the three amino acids. The linear ranges of Trp, Tyr and Cys were 0.1-119, 0.2-107 and 0.15-64muM with correlation coefficients of 0.9994, 0.9985 and ... Talanta journals http://www.medworm.com/rss/comments.php?id=3276688 Wed, 17 Feb 2010 08:38:15 +0100 3276688 http://www.medworm.com/index.php?rid=3276687&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%3D20152471%26dopt%3DAbstract Authors: Zaksas NP, Gerasimov VA, Nevinsky GA Availability of many biological samples in ample quantity for biomedical investigations sometimes is very restricted. Therefore, there is the need for the simple techniques allowing the analysis of small amount samples. In the present work the two-jet plasma atomic emission spectrometry techniques for the determination of Fe, P, Ca, Mg, Zn, and Cu in whole blood are proposed. The first technique is developed for direct analysis of freeze-dried blood. The sample preparation consisted in a dilution of blood powder (particle size 20mum or less) with a spectroscopic buffer (graphite powder containing 15wt.% NaCl). For the analysis of liquid whole blood, previous carbonization (not ashing) of blood evaporated on graphite powder was applied. Cali... Talanta journals http://www.medworm.com/rss/comments.php?id=3276687 Wed, 17 Feb 2010 08:38:12 +0100 3276687 http://www.medworm.com/index.php?rid=3276686&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%3D20152472%26dopt%3DAbstract Authors: Percy DW, Adcock JL, Conlan XA, Barnett NW, Gange ME, Noonan LK, Henderson LC, Francis PS Acidic potassium permanganate chemiluminescence was explored as a sensitive and selective mode of detection for phenolic phenethylamines (adrenergic amines) in consumer products containing Citrus aurantium extracts. Nine commercially available weight-loss products were analysed using rapid reversed-phase chromatography with a monolithic column (separation time of 4min). The results were in good agreement with package labelling, with some notable exceptions. The products contained a wide concentration range of synephrine and total adrenergic amines, and the difference in consumer intake was even greater when the manufacturers' recommended daily consumption was considered. The quantity of t... Talanta journals http://www.medworm.com/rss/comments.php?id=3276686 Wed, 17 Feb 2010 08:38:09 +0100 3276686 http://www.medworm.com/index.php?rid=3276685&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%3D20152473%26dopt%3DAbstract Authors: Robaszkiewicz A, Bartosz G Peroxynitrite and hypochlorite are oxidants relevant in many pathological situations. We propose a simple spectrofluorometric assay to determine antioxidant capacity against hypochlorite and peroxynitrite based on protection against fluorescein bleaching. The assay can be performed on a microplate and requires minute amounts of material. Standard antioxidants show different reactivities for both oxidants. Antioxidant capacity of fruit bodies of edible mushrooms, tea, coffee and wine estimated as exemplary biological material point to considerable differences in the scavenging capacity of various biological material against hypochlorite, peroxynitrite and peroxyl radicals. PMID: 20152473 [PubMed - as supplied by publisher] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=3276685 Wed, 17 Feb 2010 08:38:06 +0100 3276685 http://www.medworm.com/index.php?rid=3194554&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%3D20082804%26dopt%3DAbstract Authors: Capelo JL, Lodeiro C, Santos HM PMID: 20082804 [PubMed - in process] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=3194554 Fri, 22 Jan 2010 04:58:44 +0100 3194554 http://www.medworm.com/index.php?rid=3194553&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%3D20082805%26dopt%3DAbstract Authors: Capelo JL, Carreira RJ, Fernandes L, Lodeiro C, Santos HM, Simal-Gandara J Nowadays isotopic (18)O-labeling of peptides has recalled the attention of researchers due to its simplicity of application and high versatility for proteomics studies. Protein quantification, differential peptide mass mapping, studies regarding proteins overexpressed or underexpressed, or the searching of biomarkers can be accomplished by using (18)O-labeling. In this critical review we comment on the different ways in which (18)O-labeling can be done, highlighting the key parameters of the different sample treatments to obtain a reliable and reproducible labeling. In addition we describe and compare the latest improvement in terms of sample treatment that allows to reduce the handling and to increase ... Talanta journals http://www.medworm.com/rss/comments.php?id=3194553 Fri, 22 Jan 2010 04:58:41 +0100 3194553 http://www.medworm.com/index.php?rid=3194552&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%3D20082806%26dopt%3DAbstract This study, for the first time, shows the ability of the relative protein quantification based upon ICPL and 2D-LC-MS/MS to quantify serum biomarkers. It provides two additional label-free approaches that could validate and bring additional value to the label-based results, offering a starting point for comprehensive proteomics studies aiming at revealing biomarkers of clinical relevance. PMID: 20082806 [PubMed - in process] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=3194552 Fri, 22 Jan 2010 04:58:38 +0100 3194552 http://www.medworm.com/index.php?rid=3194551&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%3D20082807%26dopt%3DAbstract Authors: Paradela A, Marcilla M, Navajas R, Ferreira L, Ramos-Fernandez A, Fernández M, Mariscotti JF, García-del Portillo F, Albar JP An evaluation of the ICPL (isotope-coded protein labeling) non-isobaric labeling technique was performed using two different biological models. Two samples containing phage T4 capsids were mixed in a 1:1 ratio after being labeled with the light or heavy versions of the ICPL reagent. The analysis of this proteome demonstrated the feasibility of this approach for differential quantitative proteomics and was employed to optimize the experimental parameters of the ICPL workflow. ICPL-mediated analysis of two more complex proteomes, those of a Salmonella enterica serovar Typhimurium virulent strain and an isogenic attenuated mutant, and its compari... Talanta journals http://www.medworm.com/rss/comments.php?id=3194551 Fri, 22 Jan 2010 04:58:35 +0100 3194551 http://www.medworm.com/index.php?rid=3194550&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%3D20082808%26dopt%3DAbstract Authors: Abello N, Barroso B, Kerstjens HA, Postma DS, Bischoff R Protein tyrosine nitration (PTN) is a post-translational modification of proteins associated with a number of inflammatory diseases. While PTN is rather selective (not all proteins are modified and within a protein, only certain tyrosines are subject to nitration), no consensus sequence has been identified. Since PTN is a low-abundance post-translational modification, it is necessary to enrich modified proteins and/or to detect them with high selectivity and sensitivity. Until now this has been mostly accomplished with anti-nitrotyrosine antibodies in combination with two-dimensional gel electrophoresis and mass spectrometry. We propose a chemical labeling approach designed to allow enrichment of tyrosine-nitrated peptid... Talanta journals http://www.medworm.com/rss/comments.php?id=3194550 Fri, 22 Jan 2010 04:58:32 +0100 3194550 http://www.medworm.com/index.php?rid=3194549&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%3D20082809%26dopt%3DAbstract In this study, we present a systematic investigation on the effect of plasma instrumental conditions on the oxide ion responses by a design of experiment approach for the simultaneous ICP-QMS determination of P and S ((31)P(16)O(+) and (32)S(16)O(+), respectively) in protein samples without the use of dynamic reaction, collision reaction cells or pre-addition of oxygen as reactant gas in the torch. The proposed method was evaluated in terms of limit of detection, limit of quantification, linearity, repeatability, and trueness. Moreover, detection and quantification capabilities of the optimized method were compared to the standard plasma mode for determination of (31)P(+) and (34)S(+). Spectral and non-spectral interferences affecting the quantification of (31)P(+), (31)P(16)O(+) and (32)S... Talanta journals http://www.medworm.com/rss/comments.php?id=3194549 Fri, 22 Jan 2010 04:58:29 +0100 3194549 http://www.medworm.com/index.php?rid=3194548&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%3D20082810%26dopt%3DAbstract Authors: Zhou H, Hou W, Lambert JP, Tian R, Figeys D We developed a new method consisting of the proteomic reactor coupled with step pH fractionation for the analysis of low-abundance proteins from minute amount of sample. These new reactors were implemented using both SAX and SCX materials. The pH fractions from the SAX reactor provided higher peptide and protein identification than SCX reactor and conventional solution digestion. Interestingly, the physical characteristics (pI, molecular weight, missed cleavage site and grand average hydrophobicity (GRAVY) index, and number of acid and basic amino acid) of the peptides obtained from the SAX and SCX proteomic reactors are drastically different. Furthermore, nearly half of the peptides observed from the pH fractionations from the SAX r... Talanta journals http://www.medworm.com/rss/comments.php?id=3194548 Fri, 22 Jan 2010 04:58:27 +0100 3194548 http://www.medworm.com/index.php?rid=3194547&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%3D20082811%26dopt%3DAbstract Authors: Terracciano R, Casadonte F, Pasqua L, Candeloro P, Di Fabrizio E, Urbani A, Savino R Promising profiling techniques based on new material/solid phase extraction for capturing "molecular signatures" from body fluids are being coupled to MALDI-TOF-MS. Sample preparation significantly influences spectrum quality in this ionization method. Mesoporous silica beads (MSB), by the means of nano-sized porous channels with high surface area, enable harvesting of peptides from plasma and serum excluding large size proteins. We have investigated the morphology of a sample slurry, developed as a new tool for plasma peptides enrichment based on mesoporous materials. Our study highlights a correlation between crystals morphology and enhanced performances in MALDI-TOF-MS analysis. This is the... Talanta journals http://www.medworm.com/rss/comments.php?id=3194547 Fri, 22 Jan 2010 04:58:24 +0100 3194547 http://www.medworm.com/index.php?rid=3194546&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%3D20082812%26dopt%3DAbstract Authors: Weinkauf M, Hutter G, Zimmermann Y, Hartmann E, Rosenwald A, Dreyling M Despite recent advances in treatment, mantle cell lymphoma (MCL) still represents a disease with dismal prognosis due to its progressive clinical course, high rate of therapy refractory cases and frequent relapses. During recent years, the proteasome inhibitor bortezomib and enzastaurin, an inhibitor of protein kinase c have been explored in MCL. In relapsed disease enzastaurin achieved disease stabilization in a subset of patients. Bortezomib in relapsed and refractory MCL achieves response rates of 30-40%. To identify signal pathways and manifold interactions regulating cellular response to molecular targeted approaches several high throughput screening methods were applied. A combined network analysis o... Talanta journals http://www.medworm.com/rss/comments.php?id=3194546 Fri, 22 Jan 2010 04:58:21 +0100 3194546 http://www.medworm.com/index.php?rid=3194545&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%3D20082813%26dopt%3DAbstract Authors: da Silva MA, Garcia JS, de Souza GH, Eberlin MN, Gozzo FC, Arruda MA Six protocols for extraction of proteins from sunflower (Helianthus annuus L.) leaves were evaluated for their abilities in both removing interferents and attaining the best resolution in two-dimensional gel electrophoresis. "Classical" phenol extraction followed by precipitation with ammonium acetate in methanol displayed the most efficient protocol, which allowed the detection of 244 protein spots with ca. 485mug of protein in gel electrophoresis. Tandem mass spectrometry was performed to identify proteins in 61 spots, and cross species identification was used for this task. Proteins from twenty two spots were identified, and 12 of these proteins are up to now not included into the ExPASy sunflower protein ... Talanta journals http://www.medworm.com/rss/comments.php?id=3194545 Fri, 22 Jan 2010 04:58:16 +0100 3194545 http://www.medworm.com/index.php?rid=3194544&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%3D20082814%26dopt%3DAbstract Authors: Ruiz-Romero C, Calamia V, Carreira V, Mateos J, Fernández P, Blanco FJ Due to the complex structure of the articular joint, it requires great effort to fully understand joint disease pathogenesis. The proteomic analysis of articular joint tissues could contribute greatly to our insight into the endogenous control mechanisms of matrix turnover and the unravelling of the molecular and cellular mechanisms involved in the progression of the arthritides. To date, most proteome analysis strategies use the two-dimensional gel electrophoresis (2-DE) technique to separate proteins according to their isoelectric point, molecular mass, solubility and relative abundance. In this work, we describe optimization of human joint sample preparation techniques to obtain high quality 2-DE ma... Talanta journals http://www.medworm.com/rss/comments.php?id=3194544 Fri, 22 Jan 2010 04:58:13 +0100 3194544 http://www.medworm.com/index.php?rid=3194543&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%3D20082815%26dopt%3DAbstract Authors: Franco CF, Mellado MC, Alves PM, Coelho AV A new application of intact cell MALDI-TOF MS (ICM-MS) methodology is described for monitoring the production of viral proteins and viral like particles using the baculovirus/insect cells expression system. Various MALDI matrices, cell preparation methods, cell/matrix volume ratio and MALDI target application procedures were tested in order to obtain the highest intensity and reproducibility of intact insect cell spectra. The web interface, SPECLUST (http://bioinfo.thep.lu.se/speclust.html), was used to construct dendograms based on MALDI-TOF MS data for evaluation of fingerprint changes. We demonstrate that insect cell mass spectrum fingerprints are characteristic of each viral protein/particle production. Their changes along the tim... Talanta journals http://www.medworm.com/rss/comments.php?id=3194543 Fri, 22 Jan 2010 04:58:10 +0100 3194543 http://www.medworm.com/index.php?rid=3194542&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%3D20082816%26dopt%3DAbstract Authors: Hu W, Tedesco S, Faedda R, Petrone G, Cacciola SO, O'Keefe A, Sheehan D Protein thiols contribute significantly to antioxidant defence and selective oxidation of cysteines is important in signal transduction even in sub-stress scenarios. However, cysteine is the second rarest residue in proteins and it can be difficult to target low-abundance thiol (-SH)-containing proteins in proteomic separations. Activated thiol sepharose (ATS) allows covalent selection of -SH-containing proteins which can then be recovered by reduction with mercaptoethanol or dithiothreitol. This is a robust method for enriching -SH-containing proteins. We have used ATS to estimate the percentage (by weight) of thiol-containing proteins in cell extracts from a range of biological sources: a bacterium, Esch... Talanta journals http://www.medworm.com/rss/comments.php?id=3194542 Fri, 22 Jan 2010 04:58:08 +0100 3194542 http://www.medworm.com/index.php?rid=3194541&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%3D20082817%26dopt%3DAbstract This study represents a major step forward, as most previous studies identified proteins either on the basis of sequence similarity to proteins from other organisms (44% of the proteins identified in this study) or by prediction (50% of proteins identified in this study) alone. PMID: 20082817 [PubMed - in process] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=3194541 Fri, 22 Jan 2010 04:58:05 +0100 3194541 http://www.medworm.com/index.php?rid=2909674&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%3D19836497%26dopt%3DAbstract Authors: Anthemidis AN, Ioannou KI This review aims to provide an overview of homogeneous liquid-liquid extraction (HLLE) and dispersive liquid-liquid microextraction (DLLME) methods and their potential use in inorganic analysis. Relevant applications to the determination of metal ions, metalloids and organometals are included. The phase separation mechanisms of these unconventional solvent extraction techniques are discussed. The new trends in the field of miniaturization and automation are presented, while proposing future trends and potential new areas for their application. PMID: 19836497 [PubMed - in process] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=2909674 Wed, 21 Oct 2009 11:12:37 +0100 2909674 http://www.medworm.com/index.php?rid=2909673&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%3D19836498%26dopt%3DAbstract Authors: Min D, Kang N, Moon DM, Lee JB, Lee DS, Kim JS Carbon dioxide (CO(2)) is a greenhouse gas that makes by far the largest contribution to the global warming of the Earth's atmosphere. For the measurements of atmospheric CO(2) a non-dispersive infrared analyzer (NDIR) and gas chromatography are conventionally being used. We explored whether and to what degree argon content can influence the determination of atmospheric CO(2) using the comparison of CO(2) concentrations between the sample gas mixtures with varying Ar amounts at 0 and 18.6mmolmol(-1) and the calibration gas mixtures with Ar at 8.4, 9.1, and 9.3mmolmol(-1). We newly discovered that variation of Ar content in calibration gas mixtures could undermine accuracy for precise and accurate determination of atmospheric CO(2)... Talanta journals http://www.medworm.com/rss/comments.php?id=2909673 Wed, 21 Oct 2009 11:12:34 +0100 2909673 http://www.medworm.com/index.php?rid=2909672&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%3D19836499%26dopt%3DAbstract Authors: Santos MC, Wagner M, Wu B, Scheider J, Oehlmann J, Cadore S, Becker JS An imaging mass spectrometric method using laser ablation inductively coupled plasma spectrometry (LA-ICP-MS) was developed to determine Cu, Zn, Cd, Hg and Pb and metal distribution in longitudinal tissue sections of the marine snail Nassarius reticulatus (Gastropoda, Prosobranchia). Snails were sampled in northern Brittany (France) at three stations with different contamination levels. The quantification of metal distribution (imaging or mapping) in a thin slice of the snail tissue was carried out using different strategies: by one-point calibration and via matrix-matched laboratory standards using different biological materials (BCR 278, snail tissue, and rat brain). Together with the imaging of metals th... Talanta journals http://www.medworm.com/rss/comments.php?id=2909672 Wed, 21 Oct 2009 11:12:32 +0100 2909672 http://www.medworm.com/index.php?rid=2909671&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%3D19836500%26dopt%3DAbstract Authors: de Vallejuelo SF, Barrena A, Arana G, de Diego A, Madariaga JM The 3051 USEPA method (or alternatively, the 3051A) can be considered nowadays as a reference method to extract metals from sediments. However, after microwave heating, the sample must be allowed to cool down, which results in a considerable lengthening of the whole analytical process. Microwave ovens and their maintenance are, in addition, expensive, and its use is relatively dangerous. The use of ultrasound focused energy to assist the extraction of chemicals from solid samples is a safe and relatively cheap technique. In this work we propose a new method to extract simultaneously several elements from sediments using ultrasound energy focused in a glass probe to accelerate the process, and check its possibilitie... Talanta journals http://www.medworm.com/rss/comments.php?id=2909671 Wed, 21 Oct 2009 11:12:29 +0100 2909671 http://www.medworm.com/index.php?rid=2909670&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%3D19836501%26dopt%3DAbstract Authors: Hou S, He H, Zhang W, Xie H, Zhang X Determination of amino acids by mass spectrometry (MS) is an important technique to investigate soil nitrogen transformation and cycling as amino acids being the major nitrogen-containing compounds in soil organic matter. However, researchers have long faced a critical problem in coupling an efficient separation technique to a sensitive MS detection system simultaneously. In this context, we established a new method of liquid chromatography coupled to mass spectrometry based on the 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) derivatization method for convenient and accurate quantification of amino acids in soil samples. Baseline separation of 17 amino acid AQC-derivatives was achieved on an XTerra(R) MS C(18) column using ammonium... Talanta journals http://www.medworm.com/rss/comments.php?id=2909670 Wed, 21 Oct 2009 11:12:27 +0100 2909670 http://www.medworm.com/index.php?rid=2909669&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%3D19836502%26dopt%3DAbstract Authors: Gao Y, Xu Y, Han B, Li J, Xiang Q CE/Ru(bpy)(3)(2+) electrochemiluminescence (ECL) system with the assistance of ionic liquids (ILs) was successfully established for sensitive determination of verticine and verticinone in Bulbus Fritillariae for the first time. Migration behavior of alkaloid largely relies on the hydrogen bonding interactions between alkyl imidazolium cations in ILs and the alkaloids. Running buffer containing 40mmol/L 1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF(4)) IL-8mmol/L phosphate resulted in significant changes in separation selectivity for alkaloids with similar structures. The highest sensitivity of the detection was obtained by maintaining the detection potential at 1.2V. Under the optimized conditions, relative standard derivations of the ... Talanta journals http://www.medworm.com/rss/comments.php?id=2909669 Wed, 21 Oct 2009 11:12:24 +0100 2909669 http://www.medworm.com/index.php?rid=2909668&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%3D19836503%26dopt%3DAbstract Authors: Hu S, Yang H, Cai R, Liu Z, Yang X A novel method to significantly enhance fluorescence resonance energy transfer (FRET) signal which occurred from fluoresceine isothiocyanate (FITC) to Dylight 549 was studied in this paper. Streptavidin was labeled with the donor fluorophore FITC and biotinamide was conjugated to the acceptor Dylight 549. When biotinamide bound to streptavidin, FRET would occur from FITC to Dylight 549 while a remarkable fluorescence enhancement of streptavidin-FITC was observed. The fluorescence enhancement of streptavidin-FITC in the presence of biotin was utilized in the FRET system to obtain higher fluorescence signal. Increase of fluorescence intensity of FITC and decrease of Dylight 549 depended on the concentration of competitive biotin. A homogeneous ... Talanta journals http://www.medworm.com/rss/comments.php?id=2909668 Wed, 21 Oct 2009 11:12:21 +0100 2909668 http://www.medworm.com/index.php?rid=2909667&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%3D19836504%26dopt%3DAbstract Authors: Kong DM, Wu J, Wang N, Yang W, Shen HX The peroxidase activities of the complexes of hemin and intermolecular four-stranded G-quadruplexes formed by short-stranded X(n)G(m)X(p) sequences (X=A, T or C), especially T(n)G(m)T(p) sequences, were compared. The results, combining with those of circular dichroism (CD) spectra and acid-base transition study for DNA-hemin complexes, provide some important information about DNAzymes based on G-quadruplex-hemin complexes, such as the formation of a G-quadruplex structure is an important factor for determining whether a DNA sequence can enhance the catalytic activity of hemin; both intramolecular parallel G-quadruplexes and intermolecular four-stranded parallel G-quadruplexes can enhance the catalytic activity of hemin; the addition of T ... Talanta journals http://www.medworm.com/rss/comments.php?id=2909667 Wed, 21 Oct 2009 11:12:19 +0100 2909667 http://www.medworm.com/index.php?rid=2909666&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%3D19836505%26dopt%3DAbstract Authors: Boltovets PM, Snopok BA The sensitivity of surface plasmon resonance (SPR) transducers depends on the thickness and spatial organization of interfacial structures at their surfaces. This is because the response of the SPR sensor is determined by integrating the distance-dependent refractive index (spatial interfacial architectures), weighted by the square of the electromagnetic field, from zero to infinite distance. The effect of SPR transducer sensitivity variation on the accuracy of SPR analysis is considered. Our quantitative estimation (based on the results of refractometric studies) gave a value for sensitivity variation of about 3% for the formation of a self-assembled thiocyanate layer or a trypsin-soybean trypsin inhibitor surface complex. The estimated accuracy in mea... Talanta journals http://www.medworm.com/rss/comments.php?id=2909666 Wed, 21 Oct 2009 11:12:17 +0100 2909666 http://www.medworm.com/index.php?rid=2909665&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%3D19836506%26dopt%3DAbstract Authors: Cruz J, Bautista M, Amigo JM, Blanco M Near Infrared Chemical Imaging (NIR-CI) is demonstrating an increasing interest in pharmaceutical research since it meets the challenging analytical needs of pharmaceutical quality and may serve as a versatile adjunct to conventional NIR spectroscopy in many fields. The direct analysis of samples by using hyperspectral imaging techniques, which provide a NIR spectrum in each pixel of the image, generates a big amount of information from one sample. Focusing the interest in pharmaceutical research, several chemometric algorithms are demonstrating their usefulness extracting the relevant information (i.e. quantitative determination of the component in one sample) in tablets with only one sample and without damaging it. In this work, a quant... Talanta journals http://www.medworm.com/rss/comments.php?id=2909665 Wed, 21 Oct 2009 11:12:14 +0100 2909665 http://www.medworm.com/index.php?rid=2909664&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%3D19836507%26dopt%3DAbstract Authors: Gao D, Li F, Song J, Xu X, Zhang Q, Niu L A simple and environment friendly chemical route for detecting latent fingermarks by one-step single-metal nanoparticles deposition method (SND) was achieved successfully on several non-porous items. Gold nanoparticles (AuNPs) synthesized using sodium borohydride as reducing agent in the presence of glucose, were used as working solution for latent fingermarks detection. The SND technique just needs one step to obtain clear ridge details in a wide pH range (2.5-5.0), whereas the standard multi-metal deposition (MMD) technique requires six baths in a narrow pH range (2.5-2.8). The SND is very convenient to detect latent fingermarks in forensic scene or laboratory for forensic operators. The SND technique provided sharp and clear develop... Talanta journals http://www.medworm.com/rss/comments.php?id=2909664 Wed, 21 Oct 2009 11:12:11 +0100 2909664 http://www.medworm.com/index.php?rid=2909663&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%3D19836508%26dopt%3DAbstract Authors: Cao Q, Zhao H, Zeng L, Wang J, Wang R, Qiu X, He Y A novel and simple electrochemical method for determination of melamine is developed based on oligonucleotides film modified gold electrodes. The electrochemical probe of ferricyanide was used to investigate the interactions between oligonucleotides and melamine. Results of cyclic voltammetries, differential pulse stripping voltammetries, electrochemical impedance spectrometry and atomic force microscope, proved that melamine might interact with oligonucleotides mainly through electrostatic and hydrogen-bonding interactions. The interactions between oligonucleotides and melamine lead to the increase in the peak currents of ferricyanide, which could be used for electrochemical sensing of melamine. The redox peak currents of fer... Talanta journals http://www.medworm.com/rss/comments.php?id=2909663 Wed, 21 Oct 2009 11:12:08 +0100 2909663 http://www.medworm.com/index.php?rid=2909661&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%3D19836509%26dopt%3DAbstract Authors: Cantarelli MA, Funes IG, Marchevsky EJ, Camiña JM A method for the determination of oleic acid in sunflower seeds is proposed. One hundred samples of sunflower seeds were analyzed by near-infrared diffuse reflectance spectroscopy (NIRDRS). The direct measures were realized in ground and sifted seeds. The PLS multivariate calibration model was obtained using first derivate absorbance values as response matrix, while the oleic acid concentration matrix was obtained analyzing the seed samples by gas chromatography with a flame ionization detector (GC-FID). The NIRDRS-PLS model was validated externally using unknown samples of sunflower seeds. The accuracy and precision of the method was evaluated using GC as reference method. The following figures of merit (FOM) were obtaine... Talanta journals http://www.medworm.com/rss/comments.php?id=2909661 Wed, 21 Oct 2009 11:12:05 +0100 2909661 http://www.medworm.com/index.php?rid=2909659&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%3D19836510%26dopt%3DAbstract Authors: Chou TY, Lin SL, Fuh MR Partitioned dispersive liquid-liquid microextraction (PDLLME), using THF as the dispersive solvent and dichloromethane as the extraction solvent, was utilized to isolate and concentrate phenylurea herbicides (PUHs) from aqueous samples. In PDLLME, a dispersive solvent should be able to partition in the organic extractant droplets to effectively extract the polar organic compounds from aqueous samples. The mixture of the water-immiscible extractant and the partitioned dispersive solvent was obtained by centrifugation, dried under low pressure, reconstituted in methanol-water mixture (1:1), and injected into a HPLC system for the determination of PUHs. The enrichment factors of the PUHs ranged from 68 to 126 under the optimal conditions. The linear range ... Talanta journals http://www.medworm.com/rss/comments.php?id=2909659 Wed, 21 Oct 2009 11:12:02 +0100 2909659 http://www.medworm.com/index.php?rid=2909658&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%3D19836511%26dopt%3DAbstract Authors: Zimmer M, Oltersdorf A, Rentsch J Etching of silicon with mixtures of hydrofluoric acid and nitric acid is a widely used process in silicon solar cell fabrication. One precondition for an optimized usage of the acidic etching baths is the exact knowledge of the chemical bath composition. In this paper, we investigated a fast and online-capable method for the total analysis of all bath constituents by ion chromatography. The chromatographical system consists of a low-volume injection valve, which injects the concentrated samples directly into the KOH-based eluent. After separation and detection of nitrate and fluoride, a post-column derivatization with sodium molybdate is applied to detect the hexafluorosilicic acid, which enriches in the texturisation bath during the etching p... Talanta journals http://www.medworm.com/rss/comments.php?id=2909658 Wed, 21 Oct 2009 11:12:00 +0100 2909658 http://www.medworm.com/index.php?rid=2909657&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%3D19836512%26dopt%3DAbstract Authors: Zúñiga MC, Jover E, Arancibia V, Bayona JM A method for the extraction of triethyl lead (TEL(+)), trimethyl lead (TML(+)), and Pb(2+) from sand was developed using supercritical modified CO(2)-CH(3)OH extraction and in situ complexation with sodium diethyldithiocarbamate (NaDDTC) using a 2(5) factorial exploratory design is described. The screened variables were (i) pressure (69-193bar), (ii) temperature (40-150 degrees C), (iii) ligand amount (0-100mg), (iv) methanol volume (0.0-0.5mL) and (v) static time (0-45min). The optimum extraction conditions found were as follow: pressure, 193bar; temperature, 40 degrees C; amount of NaDDTC, 100mg; methanol volume, 0.5mL; static time 45min; and CO(2) flow rate, 1mLmin(-1). Under these conditions the following recoveries were... Talanta journals http://www.medworm.com/rss/comments.php?id=2909657 Wed, 21 Oct 2009 11:11:57 +0100 2909657 http://www.medworm.com/index.php?rid=2909656&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%3D19836513%26dopt%3DAbstract Authors: Atta NF, Abdel-Mageed AM A hybrid sol-gel material formed by acid hydrolysis of a mixture of tetraethylorthosilicate (TEOS) and phenyltriethylorthosilicate (PTEOS) as functional monomers was imprinted by tyramine and dopamine as template molecules for the purpose of molecular recognition. Imprinted materials were spin coated as thin films on the surface of glassy carbon electrodes and then were characterized using cyclic voltammetry (CV). After extraction of the encapsulated molecules, imprinted films were tested in solutions of their templates and other molecules. Rebinding experiments were followed by electrochemical characterization using square wave voltammetry (SWV). Imprinted films showed higher affinities toward their template molecules compared to other structurally si... Talanta journals http://www.medworm.com/rss/comments.php?id=2909656 Wed, 21 Oct 2009 11:11:55 +0100 2909656 http://www.medworm.com/index.php?rid=2909655&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%3D19836514%26dopt%3DAbstract Authors: Martinez MT, Lima AS, Bocchi N, Teixeira MF The preparation and electrochemical characterization of a carbon paste electrode modified with layered birnessite-type manganese oxide for use as a sodium sensor is described. The effects of powder synthesis process (sol-gel and redox precipitation) for birnessite on the electrochemical activity of the sensor was investigated by cyclic voltammetry. The carbon paste electrode modified with birnessite-type manganese oxide that was synthesized by the sol-gel method showed a best electrochemical for sodium ions. The detection is based on the measurement of anodic current generated by oxidation of Mn(III) to Mn(IV) at the surface of the electrode and consequently the sodium ions extraction into the birnessite structure. The best voltammet... Talanta journals http://www.medworm.com/rss/comments.php?id=2909655 Wed, 21 Oct 2009 11:11:52 +0100 2909655 http://www.medworm.com/index.php?rid=2909654&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%3D19836515%26dopt%3DAbstract Authors: Gupta M, Jain A, Verma KK A simple and rapid method has been reported for the determination of carbonyl compounds involving reaction with 2,4-dinitrophenylhydrazine and extraction of hydrazones with water-miscible organic solvent acetonitrile when the phase separation occurs by addition of ammonium sulphate, a process called salt-assisted liquid-liquid microextraction. The extract was analyzed by high-performance liquid chromatography with UV detection at 360nm. The procedure has been optimized with respect to solvent suitable for extraction, salt for phase separation between water and organic solvent, reaction temperature and reaction time. The method has been validated when a linear dynamic range was obtained between the amount of analyte and peak area of hydrazones in the r... Talanta journals http://www.medworm.com/rss/comments.php?id=2909654 Wed, 21 Oct 2009 11:11:49 +0100 2909654 http://www.medworm.com/index.php?rid=2909653&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%3D19836516%26dopt%3DAbstract Authors: Misra A, Shahid M, Dwivedi P An efficient colorimetric chemosensor with a thiourea binding site and 2-amino-6-nitrobenothiazole as a signaling unit has been synthesized by dithiocarbamate approach. The chemosensor has been utilized for selective recognition of fluoride and acetate anions in dry DMSO solution by UV-vis and (1)H NMR titration experiments. The chemosensor has shown naked-eye sensitivity for both the anions in solution. PMID: 19836516 [PubMed - in process] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=2909653 Wed, 21 Oct 2009 11:11:47 +0100 2909653 http://www.medworm.com/index.php?rid=2909652&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%3D19836517%26dopt%3DAbstract Authors: Chen W, Tang J, Cheng HJ, Xia XH Nickel hexacyanoferrate film modified gold electrode was prepared by a simple chemical deposition procedure from a fresh prepared solution containing ferricyanide, Ni(2+), and sodium nitrate. The resultant films have solo composition and are significantly stable as compared to the electrochemically deposited NiHCF films. For different concentrations of Na(+) in the solution, the formal potential values of NiHCF shift according to the Nernstian behavior with a slope of 48mV in the range of 10(-4) to 1.0M. The NiHCF film was also used for the electrocatalytic oxidation of ascorbic acid. The anodic peak current observed in cyclic voltammetry increased with the ascorbic acid concentration. At a fixed potential under hydrodynamic conditions, the cal... Talanta journals http://www.medworm.com/rss/comments.php?id=2909652 Wed, 21 Oct 2009 11:11:44 +0100 2909652 http://www.medworm.com/index.php?rid=2909651&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%3D19836518%26dopt%3DAbstract Authors: Liu J, Zhu F, Liu Z A new on-line preconcentration technique called borate complexation-assisted field-enhanced sample injection (BCA-FESI) was proposed for preconcentrating cis-diol-containing compounds (CDCCs) in capillary electrophoresis (CE). The principle relies on amplification of the difference in the electrophoretic mobilities of CDCC in sample matrix and background electrolyte (BGE) through complexation of CDCC with borate in a sample matrix of basic pH and dissociation of the complex in a BGE of acidic pH. Meanwhile, CDCC and borate ions electro-injected into the capillary are finally in neutral state, which maintains the pre-filled low conductivity zone and thus allows for longer injection time. With catechol as a test compound, the principle and effectiveness of BC... Talanta journals http://www.medworm.com/rss/comments.php?id=2909651 Wed, 21 Oct 2009 11:11:42 +0100 2909651 http://www.medworm.com/index.php?rid=2909650&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%3D19836519%26dopt%3DAbstract This study integrated dielectrophoresis (DEP) with non-flow through biochips to enhance the immuno-capture and detection of foodborne pathogenic bacteria. It demonstrated two major functions provided by DEP to improve the chip performance: (i) concentrating bacterial cells from the suspension to different locations on the chip surface by positive and negative DEP; (ii) making the cells in close contact with the immobilized antibodies on the chip surface so that immuno-capture efficiency can be dramatically enhanced. The microchip achieved the immuno-capture efficiencies of approximately 56.0% and approximately 64.0% to Salmonella cells with 15 and 30min DEP, respectively, which were considerably higher than those of approximately 10.4% and approximately 17.6% for 15 and 30min immuno-captur... Talanta journals http://www.medworm.com/rss/comments.php?id=2909650 Wed, 21 Oct 2009 11:11:39 +0100 2909650 http://www.medworm.com/index.php?rid=2909649&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%3D19836520%26dopt%3DAbstract Authors: Nano RM, Bruns RE, Ferreira SL, Baccan N, Cadore S The quantitative determination of chemical elements in organic or biological samples is an important analytical problem. Normally the elements to be determined in the organic matrix must be transformed into a simple inorganic form. A digestion method by heating on a block digestor has been developed for the determination of Al, As, Ba, Ca, Cd, Co, Cu, Fe, Mg, Mn, V and Zn in Oyster tissue by ICP OES. A simplex centroid statistical mixture design has been used to study the effects of changing HNO(3), HCl and H(2)O(2) reagent proportions on the digestion of these samples. Response surface and principal component analyses show that the species Ca, Cd, Cu, Fe, Mg, Mn and Zn have very similar analytical tendencies under this experi... Talanta journals http://www.medworm.com/rss/comments.php?id=2909649 Wed, 21 Oct 2009 11:11:37 +0100 2909649 http://www.medworm.com/index.php?rid=2909648&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%3D19836521%26dopt%3DAbstract Authors: Shukla SK, Tiwari A, Parashar GK, Mishra AP, Dubey GC A novel humidity sensor made up of nano-crystalline zinc oxide (ZnO) film, coated onto the U-shaped typical glass substrate as a wave guide, conjugated with an optical fiber and He-Ne un-polarized laser source. The nano-crystalline zinc oxide (ZnO) was synthesized using single molecular precursor method. The resulting material was characterized with Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), thermogravimetric-differential thermal analysis (TG-DTA) and scanning electron microscopy (SEM). In the thin film, ZnO particles exhibited the wurtzite phase structure with the particle size in a diameter range of 70-80nm. The humidity sensing characteristic has been estimated by measuring the optical pe... Talanta journals http://www.medworm.com/rss/comments.php?id=2909648 Wed, 21 Oct 2009 11:11:34 +0100 2909648 http://www.medworm.com/index.php?rid=2909647&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%3D19836522%26dopt%3DAbstract This study proposed a novel approach for rapidly identifying the complicated and unpredictable metabolites of ECH, based on the powerful liquid chromatography hybrid ion trap and time of flight mass spectrometry (LC/MS-IT-TOF) analysis. Four degradation products were rapidly identified via the "fragmentation-degradation" comparisons. Five phase I and phase II metabolites of the degradation products were rapidly characterized via the crossover mass differences comparisons of their quasi-molecular ions with the potential precursors. Four direct phase I and phase II metabolites of the parent compound were identified by the mass differences analysis of the molecular ions between metabolites and the parent compound. Multiple stages of fragmentation patterns were used to confirm the metabolites ... Talanta journals http://www.medworm.com/rss/comments.php?id=2909647 Wed, 21 Oct 2009 11:11:32 +0100 2909647 http://www.medworm.com/index.php?rid=2909646&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%3D19836523%26dopt%3DAbstract Authors: Gamboa JC, Peña RC, Paixão TR, Bertotti M A novel approach was developed for nitrate analysis in a FIA configuration with amperometric detection (E=-0.48V). Sensitive and reproducible current measurements were achieved by using a copper electrode activated with a controlled potential protocol. The response of the FIA amperometric method was linear over the range from 0.1 to 2.5mmolL(-1) nitrate with a detection limit of 4.2mumolL(-1) (S/N=3). The repeatability of measurements was determined as 4.7% (n=9) at the best conditions (flow rate: 3.0mLmin(-1), sample volume: 150muL and nitrate concentration: 0.5mmolL(-1)) with a sampling rate of 60samplesh(-1). The method was employed for the determination of nitrate in mineral water and soft drink samples and the results we... Talanta journals http://www.medworm.com/rss/comments.php?id=2909646 Wed, 21 Oct 2009 11:11:28 +0100 2909646 http://www.medworm.com/index.php?rid=2909645&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%3D19836524%26dopt%3DAbstract Authors: Goyal RN, Chatterjee S, Rana AR An electrochemical protocol based on reduction is developed to determine methylprednisolone using single-wall carbon nanotubes (SWNTs) modified edge plane pyrolytic graphite electrode (EPPGE). To obtain a good sensitivity, instrumental variables were studied using Square Wave Voltammetry (SWV). The voltammetric results indicate that SWNTs modified EPPGE remarkably enhances the reduction of methylprednisolone which leads to considerable improvement of peak current with shift of peak potential to less negative values. The voltammetric current showed a linear response for methylprednisolone concentration in the range 5-500nM with a sensitivity of 98nAnM(-1). The limit of detection was estimated to be 4.5x10(-9)M. The developed method is used for th... Talanta journals http://www.medworm.com/rss/comments.php?id=2909645 Wed, 21 Oct 2009 11:11:25 +0100 2909645 http://www.medworm.com/index.php?rid=2909644&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%3D19836525%26dopt%3DAbstract In this study, we have continued development of a micromechanical resonator array that is capable of detecting PrP(c) in bovine blood serum. The sensitivity of the resonators for the detection of PrP(c) is further enhanced by the use of secondary mass labels. A pair of antibodies is used in a sandwich immunoassay format to immobilize PrP(c) on the surface of resonators and attach nanoparticles as secondary mass labels to PrP(c). Secondary mass labeling is optimized in terms of incubation time to maximize the frequency shifts that correspond to the presence of PrP(c) on the surface of resonators. Our results show that a minimum of 200pgmL(-1) of PrP(c) in blood serum can be detected using micromechanical resonator arrays. PMID: 19836525 [PubMed - in process] (Source: Talanta) Talanta journals http://www.medworm.com/rss/comments.php?id=2909644 Wed, 21 Oct 2009 11:11:23 +0100 2909644 http://www.medworm.com/index.php?rid=2909643&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%3D19836526%26dopt%3DAbstract Authors: Sherazi ST, Talpur MY, Mahesar SA, Kandhro AA, Arain S The prospect of using single bounce attenuated total reflectance (SB-ATR)-Fourier transform infrared (FTIR) spectroscopy as a rapid quantitative tool to determine the main fatty acid groups present in different edible oils was investigated. Partial least squares (PLS) calibrations were developed using SB-ATR-FTIR spectra which were associated with fatty acid groups (saturated, trans, mono- and polyunsaturated) using quantitative data obtained by gas chromatography (GC). Good calibrations were obtained for all main four fat groups (saturated, mono, trans and polyunsaturated) with excellent precision. The coefficient of determination (R(2)), root mean square error of prediction (RMSEP) and bias for validation set were obtain... Talanta journals http://www.medworm.com/rss/comments.php?id=2909643 Wed, 21 Oct 2009 11:11:20 +0100 2909643 http://www.medworm.com/index.php?rid=2909642&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%3D19836527%26dopt%3DAbstract Authors: Guo JH, Zhu LN, Kong DM, Shen HX Triphenylmethane (TPM) dyes normally render rather weak fluorescence due to easy vibrational deexcitation. However, when they stack onto the two external G-quartets of a G-quadruplex (especially intramolecular G-quadruplex), such vibrations will be restricted, resulting in greatly enhanced fluorescence intensities. Thus, TPM dyes may be developed as sensitive G-quadruplex fluorescent probes. Here, fluorescence spectra and energy transfer spectra of five TPM dyes in the presence of G-quadruplexes, single- or double-stranded DNAs were compared. The results show that the fluorescence spectra of four TPM dyes can be used to discriminate intramolecular G-quadruplexes from intermolecular G-quadruplexes, single- and double-stranded DNAs. The energy tr... Talanta journals http://www.medworm.com/rss/comments.php?id=2909642 Wed, 21 Oct 2009 11:11:18 +0100 2909642 http://www.medworm.com/index.php?rid=2909641&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%3D19836528%26dopt%3DAbstract Authors: Bielicka-Daszkiewicz K, Voelkel A Solid-phase extraction is one of the most popular sample preparation methods. The selection of the appropriate extraction system is an important stage in the elaboration of analytical procedure. In this case, the knowledge of the interactions between isolated compounds, sorbent and elution solvents seems to be important. The extraction ability of sorbents in the SPE bed depends also on: (i) the bed capacity; (ii) the volume of sample loaded, (iii) the nature and volumes of conditioning solvents and eluents. One of the important parameters is the breakthrough volume, which determines the maximum volume of water sample which can be introduced into the sorbent. In this work two methods of determination of the breakthrough volumes are presented: e... Talanta journals http://www.medworm.com/rss/comments.php?id=2909641 Wed, 21 Oct 2009 11:11:15 +0100 2909641 http://www.medworm.com/index.php?rid=2909640&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%3D19836529%26dopt%3DAbstract Authors: Perestrelo R, Nogueira JM, Câmara JS A stir bar sorptive extraction with liquid desorption followed by large volume injection coupled to gas chromatography-quadrupole mass spectrometry (SBSE-LD/LVI-GC-qMS) was evaluated for the simultaneous determination of higher alcohol acetates (HAA), isoamyl esters (IsoE) and ethyl esters (EE) of fatty acids. The method performance was assessed and compared with other solventless technique, the solid-phase microextraction (SPME) in headspace mode (HS). For both techniques, influential experimental parameters were optimised to provide sensitive and robust methods. The SBSE-LD/LVI methodology was previously optimised in terms of extraction time, influence of ethanol in the matrix, liquid desorption (LD) conditions and instrumental setti... Talanta journals http://www.medworm.com/rss/comments.php?id=2909640 Wed, 21 Oct 2009 11:11:12 +0100 2909640 http://www.medworm.com/index.php?rid=2909639&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%3D19836530%26dopt%3DAbstract Authors: Rico MA, Olivares-Marín M, Gil EP A simple procedure for the chemical synthesis of bismuth nanoparticles and subsequent adsorption on commercial screen-printed carbon electrodes offer reliable quantitation of trace zinc, cadmium and lead by anodic stripping square-wave voltammetry in nondeareated water samples. The influence of two hydrodynamic configurations (convective cell and flow cell) and the effect of various experimental variables upon the stripping signals at the bismuth-coated sensor are explored. The square-wave peak current signal is linear over the low ngmL(-1) range (120s deposition), with detections limits ranging from 0.9 to 4.9ngmL(-1) and good precision. Applicability to waste water certified reference material and drinking water samples is demonstrated.... Talanta journals http://www.medworm.com/rss/comments.php?id=2909639 Wed, 21 Oct 2009 11:11:10 +0100 2909639 http://www.medworm.com/index.php?rid=2909638&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%3D19836531%26dopt%3DAbstract Authors: Valle-Algarra FM, Mateo EM, Gimeno-Adelantado JV, Mateo-Castro R, Jiménez M Patulin (PAT) is a mycotoxin produced in fruits, mainly in apples, by several fungal species that can be carried into industrial apple juice by-products during factory processing. An analytical method for determination of PAT in apple juice and another one for determination of this compound in apple purees and apple compotes by liquid chromatography are proposed in the present paper. These methods have better precision and sensitivity than previously reported methods and focus mainly on extraction and clean-up. To accomplish analytical methods with higher accuracy, lower limits of detection and simpler procedures for application in quality control of the goods, different extraction and clean-up pr... Talanta journals http://www.medworm.com/rss/comments.php?id=2909638 Wed, 21 Oct 2009 11:11:07 +0100 2909638 http://www.medworm.com/index.php?rid=2909637&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%3D19836532%26dopt%3DAbstract Authors: Gómez-Ruiz JA, Cordeiro F, López P, Wenzl T This paper presents the optimisation of a programmed temperature vaporization solvent vent (PTV-SV) injection gas chromatographic mass spectrometric (GC-MS) method for the analysis of the 15+1 EU-priority PAHs in food extracts. Three operation parameters (vent time, vent flow and vent pressure) were optimised by applying a D-optimal experimental design. Among these variables, vent time showed the highest effect on the analytical response (signal intensity) of the target PAHs. The 15+1 EU-priority PAHs were analysed in solvent solutions and in extracts of fortified sausage. In addition, blank lamb meat extracts were prepared and spiked with the target PAHs prior to GC-MS analysis. The performance of the optimised PTV-SV inje... Talanta journals http://www.medworm.com/rss/comments.php?id=2909637 Wed, 21 Oct 2009 11:11:04 +0100 2909637 http://www.medworm.com/index.php?rid=2909636&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%3D19836533%26dopt%3DAbstract Authors: Pencík A, Rolcík J, Novák O, Magnus V, Barták P, Buchtík R, Salopek-Sondi B, Strnad M An analytical protocol for the isolation and quantification of indole-3-acetic acid (IAA) and its amino acid conjugates was developed. IAA is an important phytohormone and formation of its conjugates plays a crucial role in regulating IAA levels in plants. The developed protocol combines a highly specific immunoaffinity extraction with a sensitive and selective LC-MS/MS analysis. By using internal standards for each of the studied compounds, IAA and seven amino acid conjugates were analyzed in quantities of fresh plant material as low as 30mg. In seeds of Helleborus niger, physiological levels of these compounds were found to range from 7.5nmolg(-1) fresh weight (IAA)... Talanta journals http://www.medworm.com/rss/comments.php?id=2909636 Wed, 21 Oct 2009 11:11:02 +0100 2909636 http://www.medworm.com/index.php?rid=2909635&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%3D19836534%26dopt%3DAbstract Authors: Nasirizadeh N, Zare HR A highly efficient noradrenalin (NA) biosensor was fabricated on the basis of hematoxylin electrodeposited on a glassy carbon electrode, GCE. The cyclic voltammetric responses of the hematoxylin biosensor at various scan rates, which were obtained in a 0.25mmolL(-1) NA solution, showed the characteristic shape typical of an EC(cat) process. The kinetic parameters such as electron transfer coefficient, alpha, the catalytic electron transfer rate constant, k', and the standard catalytic electron transfer rate constant, k(0), for oxidation of NA at the hematoxylin biosensor surface were estimated using cyclic and RDE voltammetry. The peaks of differential pulse voltammetric (DPV) for NA and acetaminophen (AC) oxidation at the hematoxylin biosensor surface w... Talanta journals http://www.medworm.com/rss/comments.php?id=2909635 Wed, 21 Oct 2009 11:10:59 +0100 2909635 http://www.medworm.com/index.php?rid=2909634&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%3D19836535%26dopt%3DAbstract Authors: Parham H, Rahbar N A new, sensitive, fast and simple method using magnetic iron oxide nanoparticles (MIONs), as an adsorbent has been developed for extraction, preconcentration and determination of traces of fluoride ions. The determination method is based on the discoloration of Fe(III)-SCN complex with extracted fluoride ions which was subsequently monitored spectrophotometrically at lambda(max)=458nm. Various parameters affecting the adsorption of fluoride by the MIONs have been investigated, such as pH of the solution, type, volume and concentration of desorbing reagent, amount of adsorbent and interference effects. A linear response for the determination of fluoride was achieved in the concentration range of 0.040-1.250mugmL(-1). The limit of detection (LOD) and limit of ... Talanta journals http://www.medworm.com/rss/comments.php?id=2909634 Wed, 21 Oct 2009 11:10:56 +0100 2909634 http://www.medworm.com/index.php?rid=2909633&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%3D19836536%26dopt%3DAbstract Authors: Lacroix-Fralish A, Clare J, Skinner CD, Salin ED A centrifugal microanalysis system using spectrophotometric detection has been developed for the determination of nitrite and chromium VI. The system was designed to illustrate the potential of centrifugal microfluidic systems for on-site (field) analysis of waters. The performance was significantly better than manual/visual field test systems and approaches that of bench top systems with detection limits of 0.008mgL(-1) NO(2)(-)-N and 0.03mgL(-1) Cr(6+). The system used pre-loaded solid reagents on the disc, providing ease of use, and could process up to 24 samples simultaneously. Precision was enhanced by the use of a multiwavelength ratiometric blank estimation technique. PMID: 19836536 [PubMed - in process] (Source: Tala... Talanta journals http://www.medworm.com/rss/comments.php?id=2909633 Wed, 21 Oct 2009 11:10:53 +0100 2909633 http://www.medworm.com/index.php?rid=2909632&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%3D19836537%26dopt%3DAbstract This study evaluates the potential use of stable zinc isotopes in toxicity studies measuring zinc uptake by the gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss). The use of stable isotopes in such studies has several advantages over the use of radioisotopes, including cost, ease of handling, elimination of permit requirements, and waste disposal. A pilot study using brown trout was performed to evaluate sample preparation methods and the ability of a quadrupole inductively coupled plasma mass spectrometer (ICP-MS) system to successfully measure changes in the (67)Zn/(66)Zn ratios for planned exposure levels and duration. After completion of the pilot study, a full-scale zinc exposure study using rainbow trout was performed. The results of these studies indicate t... Talanta journals http://www.medworm.com/rss/comments.php?id=2909632 Wed, 21 Oct 2009 11:10:50 +0100 2909632 http://www.medworm.com/index.php?rid=2909631&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%3D19836538%26dopt%3DAbstract Authors: Singh AK, Singh P, Bhattacharjee G Poly(vinylchloride) (PVC) based membranes of macrocycles 2,3,4:9,10,11-dipyridine-1,3,5,8,10,12-hexaazacyclotetradeca-2,9-diene (L(1)) and 2,3,4:9,10,11-dipyridine-1,5,8,12-tetramethylacrylate-1,3,5,8,10,12-hexaazacyclotetradeca-2,9-diene (L(2)) with NaTPB and KTpClPB as anion excluders and dibutylphthalate (DBP), benzyl acetate (BA), dioctylphthalate (DOP), o-nitrophenyloctyl ether (o-NPOE) and tri-n-butylphosphate (TBP) as plasticizing solvent mediators were prepared and investigated as Co(2+) selective electrodes. The best performance was observed with the membranes having the composition L(2):PVC:TBP:NaTPB in the ratio of 6:39:53:2 (w/w; mg). The performance of the membrane based on L(2) was compared with polymeric membrane electrode (PME... Talanta journals http://www.medworm.com/rss/comments.php?id=2909631 Wed, 21 Oct 2009 11:10:47 +0100 2909631 http://www.medworm.com/index.php?rid=2909630&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%3D19836539%26dopt%3DAbstract Authors: Song X, Li J, Wang J, Chen L Molecular imprinted polymers (MIPs) were prepared through thermal polymerization by using quercetin as the template molecule, acrylamide (AA) as the functional monomer and ethylene glycol dimethacrylate (EDMA) as the cross-linker in the porogen of tetrahydrofuran (THF). The synthesized MIPs were identified by both Fourier transform infrared (FTIR) and scanning electron microscope (SEM). Systematic investigations of the influences of key synthetic conditions, including functional monomers, porogens and cross-linkers, on the recognition properties of the MIPs were conducted. Scatchard analysis revealed that the homogeneous binding sites were formed in the polymers. Besides quercetin, two structurally similar compounds of rutin and catechol were emplo... Talanta journals http://www.medworm.com/rss/comments.php?id=2909630 Wed, 21 Oct 2009 11:10:44 +0100 2909630 http://www.medworm.com/index.php?rid=2909629&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%3D19836540%26dopt%3DAbstract In this study, we present, to our knowledge, the first demonstration of alkyl-diol@SiO(2) mesoporous material MCM-41 (alkyl-diol group on the external surface of mesoporous material) for selective extraction of LMW proteins and peptides from complex biological samples. The adsorption kinetics of LMW proteins, the influence of pH on adsorption and the desorption recovery by different elution solvents were investigated by using standard proteins as model samples. It was demonstrated that the modification of alkyl-diol group on the external surface could efficiently decrease the adsorption of HMW protein and increase the desorption recovery of LMW protein. Furthermore, the mesoporous materials were applied to selectively extract LMW proteins and peptides (<10kDa) from crude human plasma. A... Talanta journals http://www.medworm.com/rss/comments.php?id=2909629 Wed, 21 Oct 2009 11:10:41 +0100 2909629