caa a22 4500 445801328 CHVBK 20180317145142.0 cr unu---uuuuu 170323e20110201xx s 000 0 eng 10.1007/s10337-010-1895-0 doi (NATIONALLICENCE)springer-10.1007/s10337-010-1895-0 Combination of Extraction by Silylated Vessel-Dispersive Liquid-Liquid Microextraction as a High-Enrichment Factor Technique: Optimization and Application in Preconcentration of Some Triazole Pesticides from Aqueous Samples Followed by GC-FID Determination [Elektronische Daten] [Mir Farajzadeh, Morteza Bahram, Farshad Jafary, Mehdi Bamorowat] This study describes an extraction method based on silylated extraction vessel-dispersive liquid-liquid microextraction (SEV-DLLME) for preconcentration of some triazole pesticides (penconazole, hexaconazole, tebuconazole, diniconazole, triticonazole, and difenconazole) from aqueous samples. For this purpose, the interior surface of funnel-shaped extraction vessel is activated by concentrated NaOH and HCl solutions, silylated by trimethylchlorosilane (TMCS) and used in extraction of the analytes from a relatively high volume of aqueous sample. The adsorbed analytes are desorbed by methanol, which acts as a dispersive solvent in the following DLLME method. In the first step, the effects of different factors i.e., concentrations of NaOH, HCl, and silylated agent and their contact times were studied using central composite design (CCD) and response surface method. Extraction time, extraction solvent (chloroform) volume, dispersive solvent (methanol) volume, centrifugation rate and time, and salting-out effect in DLLME procedure were optimized in the same way using CCD, in the second step. High enrichment factors (EFs) (more than 1,000 in most cases) and low detection limits (at sub μgL−1 level) are attainable by using gas chromatography-flame ionization detection. The repeatability and reproducibility of the proposed method are good and the relative standard deviations (RSD %) for six repeated experiments (C=100μgL−1 of each pesticide) are less than 7.25%. Finally, the method was successfully applied in determination of analytes in some aqueous samples such as wastewater, well water, and some fruit juice samples. Springer-Verlag, 2011 Dispersive liquid-liquid microextraction nationallicence Enrichment factor nationallicence Gas chromatography nationallicence Silylated extraction vessel nationallicence Triazole pesticides nationallicence Farajzadeh Mir Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran aut Bahram Morteza Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran aut Jafary Farshad Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran aut Bamorowat Mehdi GYAH Corporation, Garmdarreh, Tehran, Iran aut Chromatographia Vieweg Verlag 73/3-4(2011-02-01), 393-401 0009-5893 73:3-4<393 2011 73 10337 https://doi.org/10.1007/s10337-010-1895-0 text/html Onlinezugriff via DOI 1 brief-communication jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10337-010-1895-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Farajzadeh Mir Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran aut NATIONALLICENCE 700 1- Bahram Morteza Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran aut NATIONALLICENCE 700 1- Jafary Farshad Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran aut NATIONALLICENCE 700 1- Bamorowat Mehdi GYAH Corporation, Garmdarreh, Tehran, Iran aut NATIONALLICENCE 773 0- Chromatographia Vieweg Verlag 73/3-4(2011-02-01), 393-401 0009-5893 73:3-4<393 2011 73 10337 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer