Simultaneous enantiomeric analysis of eight pesticides in soils and river sediments by chiral liquid chromatography-tandem mass spectrometry. (August 2018)

• Record Type: Journal Article
• Authors: Zhao, Pengfei; Zhao, Jing; Lei, Shuo; Guo, Xingjie; Zhao, Longshan
• Is Part Of: Chemosphere. Volume 204(2018)
• Page Start: 210
• Page End: 219
• Publication Date: 2018-08
• Subjects: Chiral analysis -- Enantiomeric composition -- Pesticides -- Soil -- River sediment -- Liquid chromatography tandem mass spectrometry; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2018.03.204
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: A rapid and sensitive multi-residue method was developed for the simultaneous quantification of eight chiral pesticides (including diniconazole, metalaxyl, paclobutrazol, epoxiconazole, myclobutanil, hexaconazole, napropamide and isocarbophos) at enantiomeric levels in environmental soils and sediments using chiral liquid chromatography-tandem mass spectrometry based on a combined pretreatment of matrix solid-phase dispersion and dispersive liquid-liquid microextraction (MSPD-DLLME). Under optimized conditions, 0.1 g of solid sample was dispersed with 0.4 g of C18-bonded silica sorbent, and 3 mL of methanol was used for eluting the analytes. The collected eluant was dried and then further purified by DLLME with 550 μL of dichloromethane and 960 μL of acetonitrile as extraction and disperser solvent, respectively. The established method was validated and found to be linear, precise, and accurate over the concentration range of 2–500 ng g −1 for epoxiconazole, paclobutrazol and metalaxyl and 4–500 ng g −1 for isocarbophos, hexaconazole, myclobutanil, diniconazole and napropamide. Recoveries of sixteen enantiomers varied from 87.0 to 104.1% and the relative standard deviations (RSD) were less than 10.1%. Method detection and quantification limits (MDLs and MQLs) varied from 0.22 to 1.54 ng g −1 and from 0.91 to 4.00 ng g −1, respectively. Finally, the method was successfully applied to analyze the enantiomeric composition of the eight chiral pesticides in environmental solid matrices, which will help better understand the behavior of individual enantiomer and make accurate risk assessment on the ecosystem. Graphical abstract: Image 1 Highlights: The enantiomeric composition of eight chiral pesticides was simultaneously determined by chiral LC-MS/MS. A MSPD-DLLME technique was used for extraction and purification of the pesticides. Matrix effect was related to the physicochemical characteristics of soil/sediment. Stereoselective degradation occurred to metalaxyl in soil and river sediment.