title: Trace determination of organophosphorus pesticides in environmental samples by temperature-controlled ionic liquid dispersive liquid-phase microextraction.
abstract: This paper described a new approach for the determination of organophosphorus pesticides by temperature-controlled ionic liquid dispersive liquid-phase microextraction prior to high-performance liquid chromatography with ultraviolet detection. Methylparathion and phoxim, two of the typical organophosphorus pesticides, were used as the model analytes for the investigation of the development and application of the new microextraction method. 1-Hexyl-3-methylimidazolium hexafluorophosphate [C6MIM][PF6] was used as the extraction solvent and the factors affecting the extraction efficiency such as the volume of [C6MIM][PF6], pH of working solutions, extraction time, centrifuging time, dissoluble temperature and salt effect were optimized. Under the optimal extraction conditions, methylparathion and phoxim exhibited good linear relationship in the concentration range of 1-100 ng mL(-1). The detection limits were 0.17 ng mL(-1) and 0.29 ng mL(-1), respectively. Precisions of proposed method (RSDs, n=6) were 2.5% and 2.7%, respectively. This proposed method was successfully applied in the analysis of four real environmental water samples and good spiked recoveries over the range of 88.2-103.6% were obtained. These results indicated that temperature-controlled ionic liquid dispersive liquid-phase microextraction had excellent application prospect in environmental field.
authors.affiliation: School of Chemistry and Environmental Sciences, Henan Normal University, Henan Key Laboratory for Environmental Pollution Control, Xinxiang 453007, China. zhouqx@henannu.edu.cn
authors.forename: Qingxiang
authors.initials: Q
authors.lastname: Zhou
authors.forename: Huahua
authors.initials: H
authors.lastname: Bai
authors.forename: Guohong
authors.initials: G
authors.lastname: Xie
authors.forename: Junping
authors.initials: J
authors.lastname: Xiao
mesh_terms: D002498:Centrifugation; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D052578:Ionic Liquids / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D012492:Salts; D013696:Temperature; D013997:Time Factors
chemical_list: D004785:Environmental Pollutants; D052578:Ionic Liquids; D009943:Organophosphorus Compounds; D010575:Pesticides; D012492:Salts