title: Ultrasound-assisted dispersive liquid-liquid microextraction for the determination of six pyrethroids in river water.
abstract: A simple ultrasound-assisted dispersive liquid-liquid microextraction method combined with liquid chromatography was developed for the preconcentration and determination of six pyrethroids in river water samples. The procedure was based on a ternary solvent system to formatting tiny droplets of extractant in sample solution by dissolving appropriate amounts of water-immiscible extractant (tetrachloromethane) in watermiscible dispersive solvent (acetone). Various parameters that affected the extraction efficiency (such as type and volume of extraction and dispersive solvent, extraction time, ultrasonic time, and centrifuging time) were evaluated. Under the optimum condition, good linearity was obtained in a range of 0.00059-1.52 mg L(-1) for all analytes with the correlation coefficient (r(2))>0.999. Intra-assay and inter-assay precision evaluated as the relative standard deviation (RSD) were less than 3.4 and 8.9%. The recoveries of six pyrethroids at three spiked levels were in the range of 86.2-109.3% with RSD of less than 8.7%. The enrichment factors for the six pyrethroids were ranged from 767 to 1033 folds.
authors.affiliation: College of Pharmacy, Hebei University, Wusidong Road 180#, Baoding 071002, China. yanhy@hbu.edu.cn
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Yan
authors.forename: Baomi
authors.initials: B
authors.lastname: Liu
authors.forename: Jingjing
authors.initials: J
authors.lastname: Du
authors.forename: Gengliang
authors.initials: G
authors.lastname: Yang
authors.forename: Kyung Ho
authors.initials: KH
authors.lastname: Row
mesh_terms: D002251:Carbon Tetrachloride / Q000737:chemistry; D005591:Chemical Fractionation / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods; D016014:Linear Models; D011722:Pyrethrins / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D045483:Rivers / Q000737:chemistry*; D012680:Sensitivity and Specificity; D014465:Ultrasonics
chemical_list: D011722:Pyrethrins; D002251:Carbon Tetrachloride