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Yakupova Z. R. Lebedinets S. A. Vakh K. S. Garmonov S. Yu. Bulatov A. V. 《Journal of Analytical Chemistry》2022,77(3):342-346
Journal of Analytical Chemistry - A method is proposed for the chromatographic determination of 17-β-estradiol in medicinal preparations with the microextraction of the analyte from a sample... 相似文献
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Kseniia Medinskaia Christina Vakh Darina Aseeva Vasil Andruch Leonid Moskvin Andrey Bulatov 《Analytica chimica acta》2016
A first attempt to automate the effervescence assisted dispersive liquid–liquid microextraction (EA-DLLME) has been reported. The method is based on the aspiration of a sample and all required aqueous reagents into the stepwise injection analysis (SWIA) manifold, followed by simultaneous counterflow injection of the extraction solvent (dichloromethane), the mixture of the effervescence agent (0.5 mol L−1 Na2CO3) and the proton donor solution (1 mol L−1 CH3COOH). Formation of carbon dioxide microbubbles generated in situ leads to the dispersion of the extraction solvent in the whole aqueous sample and extraction of the analyte into organic phase. Unlike the conventional DLLME, in the case of EA-DLLME, the addition of dispersive solvent, as well as, time consuming centrifugation step for disruption of the cloudy state is avoided. The phase separation was achieved by gentle bubbling of nitrogen stream (2 mL min−1 during 2 min). 相似文献
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Christina Vakh Aleksei Pochivalov Vasil Andruch Leonid Moskvin Andrey Bulatov 《Analytica chimica acta》2016
A novel fully automated effervescence-assisted switchable solvent-based liquid phase microextraction procedure has been suggested. In this extraction method, medium-chain saturated fatty acids were investigated as switchable hydrophilicity solvents. The conversion of fatty acid into hydrophilic form was carried out in the presence of sodium carbonate. The injection of sulfuric acid into the solution decreased the pH value of the solution, thus, microdroplets of the fatty acid were generated. Carbon dioxide bubbles were generated in-situ, and promoted the extraction process and final phase separation. The performance of the suggested approach was demonstrated by the determination of ofloxacin in human urine samples using high-performance liquid chromatography with fluorescence detection. This analytical task was used as a proof-of-concept example. Under the optimal conditions, the detector response of ofloxacin was linear in the concentration ranges of 3·10−8−3·10−6 mol L−1. The limit of detection, calculated from a blank test based on 3σ, was 1·10−8 mol L−1. The results demonstrated that the presented approach is highly cost-effective, simple, rapid and environmentally friendly. 相似文献
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