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Fast Determination (fast + determination)
Selected AbstractsFast Determination of Clenbuterol and Salbutamol in Feed and Meat Products Based on Miniaturized Capillary Electrophoresis with Amperometric DetectionCHINESE JOURNAL OF CHEMISTRY, Issue 12 2007Qing-Cui CHU Abstract The fast separation capability of a novel miniaturized capillary electrophoresis with an amperometric detection (,CE-AD) system was demonstrated by determining clenbuterol and salbutamol in real samples. The effects of several factors such as the acidity and concentration of the running buffer, the separation voltage, the applied potential and the injection time on CE-AD were examined and optimized. Under the optimum conditions, the two , -agonists could be baseline separated within 60 s at a separation voltage of 2 kV in a 90 mmol/L H3BO3 -Na2B4O7 running buffer (pH 7.4), which was not interfered by ascorbic acid and uric acid. Highly linear response was obtained for above compounds over three orders of magnitude with detection limits ranging from 1.20×10,7 to 6.50×10,8 mol/L (S/N=3). This method was successfully used in the analysis of feed and meat products with relatively simple extraction procedures. [source] Fast determination of prominent carotenoids in tomato fruits by CEC using methacrylate ester-based monolithic columnsELECTROPHORESIS, Issue 22 2007Ana Maria Adalid Abstract In this study, the major carotenoids (,-carotene and lycopene) present in tomato fruits were analyzed by CEC with a methacrylate ester-based monolithic column. The effects of the porogenic solvent ratio, and the hydrophobicity of bulk monomer employed were examined on carotenoids separations. A fast separation of these analytes was achieved in less than 5.0,min in a mobile phase containing 35% THF, 30% ACN, 30% methanol, and 5% of a 5,mM Tris aqueous buffer, pH,8, with lauryl methacrylate-based monoliths. The CEC method was evaluated in terms of detection limit and reproducibility (retention time, area, and column preparation) with values below 1.6,,g/mL and 7.2%, respectively. The proposed procedure was successfully applied to the determination of both carotenoids in fruits of several tomato-related species and its usefulness to analyze large series of samples for nutritional quality screening trials in tomato breeding programs is demonstrated. To our knowledge, this is the first work that exploits the powerful and user-friendly monolithic technology for quality breeding and germplasm evaluation program purposes. [source] Modelling of photonic bandgap devices by the leaky mode propagation methodINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 3 2003Agostino Giorgio Abstract Main modelling approaches used for investigating the Photonic bandgap (PBG) devices are reviewed. In particular, the model based on Leaky Mode Propagation (LMP) method is described. A complete analysis of the propagation characteristics, including the determination of modal propagation constants, electromagnetic field harmonics and total field distribution, transmission and reflection coefficients, total forward and backward power flow in the structure, guided and radiated power, and total losses, can be carried out by a computer program based on the LMP approach. The numerical results have been validated by comparisons with those obtained by using other more complex and expensive models. The new model shows some significant advantages in terms of very low computational time, absence of any a priori theoretical assumptions and approximations, capability of simulating the actual physical behaviour of the device and fast determination of the bandgap position.Copyright © 2003 John Wiley & Sons, Ltd. [source] Evaluation of the silanol-suppressing potency of ionic liquidsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 8 2006Micha, Piotr Marsza Abstract Recently, increasing attention has been paid to the use of ionic liquids for high-performance liquid chromatography (HPLC) and capillary electrophoresis. In the present study, the silanol-suppressing potency of ionic liquids was evaluated by HPLC using the two-retention site model proposed previously by Nahum and Horváth (J. Chromatogr. 1981, 203, 53,63). The binding constant, KA, in that approach has been demonstrated to reliably reflect the ability of the ionic liquids to block the silanols of the silica support material of the stationary phase. The determinations were carried out for ionic liquids of the 1-alkyl-3-methylimidazolium group with the use of a series of basic drugs as the test analytes. Comparison of ionic liquids with standard mobile phase additives such as triethylamine showed the former to possess advantages as silanol suppressors in HPLC. The main advantage of the method is that it provides a simple and fast determination of the silanol complex stability, which allowed comparison of the suppressing efficiency of several ionic liquids. [source] Highly automated and fast determination of raffinose family oligosaccharides in Lupinus seeds using pressurized liquid extraction and high-performance anion-exchange chromatography with pulsed amperometric detectionJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2008David Bansleben Abstract BACKGROUND: Taking into account several requirements for the determination of raffinose family oligosaccharides (RFOs) from Lupinus seeds,e.g., conducting plant breeding projects or food product development,a reasonable combination of efficient automated sample preparation and reliable analysis need to be developed and validated. RESULTS: In this regard pressurized liquid extraction was applied to extract the RFOs from ground and defatted lupin flour. Compared to many other publications, no further pretreatment, such as protein precipitation, was necessary to obtain satisfactory results applying ion chromatography with pulsed amperometric detection. The oligosaccharide content for the examined Lupinus albus samples were in the range 5.19,9.25 g kg,1 and for Lupinus angustifolius RFOs 3.49,4.75 g kg,1. Stachyose has always been the main component followed by raffinose and verbascose. CONCLUSION: The developed sample preparation and analytical method is suited to quantify raffinose, stachyose, verbascose and the disaccharide sucrose and, owing to a high degree of automation for sample preparation and relatively short analysis times by pretty peak separation, particularly high sample numbers can be accomplished. Copyright © 2008 Society of Chemical Industry [source] | ||||||||||