title: Temperature-controlled ultrasound- and vortex-assisted liquid-liquid microextraction combined with GC for the determination of the concentrations of organophosphorus pesticides in beverage samples.
abstract: The aim of this work was to develop temperature-controlled ultrasound- and vortex-assisted liquid-liquid microextraction as a fast and efficient approach for the extraction of nine organophosphorus pesticides in beverage samples followed by GC with flame photometric detection analysis. The combination of ultrasonication and vortexing were used to assist the microextraction, and the use of a dispersion solvent was avoided. Several variables that could potentially affect the extraction efficiency, namely, the type and volume of extraction solvent, sequence, and time of ultrasonication and vortexing, ultrasonication bath temperature and ionic strength were optimized. Under optimum conditions, the calibration graphs were linear over the range of 0.5-200 μg/L. The LOD (S/N = 3) was between 0.01 and 0.05. The optimized method exhibited a good precision level with RSD values between 4.5 and 9.8%. The enrichment factors for the nine organophosphorus pesticides were between 224 and 339. Four beverage samples were successfully analyzed using the proposed method.
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing, China.
authors.forename: Tong
authors.initials: T
authors.lastname: Wu
authors.forename: Wenting
authors.initials: W
authors.lastname: Zhao
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Yang
authors.forename: Haixiang
authors.initials: H
authors.lastname: Gao
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhou
keywords: Beverage analysis; Liquid-liquid microextraction; Organophosphorus pesticides; Ultrasound; Vortex