title: Compound specific isotope analysis of organophosphorus pesticides.
abstract: Compound-specific isotope analysis (CSIA) has been established as a tool to study the environmental fate of a wide range of contaminants. In this study, CSIA was developed to analyse the stable carbon isotope signatures of the widely used organophosphorus pesticides: dichlorvos, omethoate and dimethoate. The linearity of the GC-C-IRMS system was tested for target pesticides and led to an acceptable isotope composition within the uncertainty of the instrument. In order to assess the accuracy of the developed method, the effect of the evaporation procedure on measured carbon isotope composition (δ(13)C) values was studied and showed that concentration by evaporation of solvents had no significant isotope effect. The CSIA was then applied to investigate isotope fractionation of the hydrolysis and photolysis of selected pesticides. The carbon isotope fractionation of tested pesticides was quantified by the Rayleigh model, which revealed a bulk enrichment factor (ε) of -0.2±0.1‰ for hydrolysis of dichlorvos, -1.0±0.1‰ and -3.7±1.1‰ for hydrolysis and photolysis of dimethoate respectively. This study is a first step towards the application of CSIA to trace the transport and degradation of organophosphorus pesticides in the environment.
authors.affiliation: School of Civil and Environmental Engineering, and National International Cooperation Based on Environment and Energy, University of Science and Technology Beijing, Xueyuan Road No. 30, Haidian District, Beijing 100083, PR China.
authors.forename: Langping
authors.initials: L
authors.lastname: Wu
authors.affiliation: School of Civil and Environmental Engineering, and National International Cooperation Based on Environment and Energy, University of Science and Technology Beijing, Xueyuan Road No. 30, Haidian District, Beijing 100083, PR China. Electronic address: yaojun@ustb.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Yao
authors.affiliation: Laboratory for Environmental Research, University of Nova Gorica, Vipavska 13, Nova Gorica SI-5000, Slovenia. Electronic address: polonca.trebse@ung.si.
authors.forename: Polonca
authors.initials: P
authors.lastname: Trebse
authors.affiliation: Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 9 15, Leipzig 04318, Germany.
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 9 15, Leipzig 04318, Germany.
authors.forename: Hans H
authors.initials: HH
authors.lastname: Richnow
mesh_terms: D002247:Carbon Isotopes / Q000032:analysis; D004006:Dichlorvos / Q000032:analysis*; D004117:Dimethoate / Q000031:analogs & derivatives* / Q000032:analysis*; D004785:Environmental Pollutants / Q000032:analysis*; D006868:Hydrolysis; D010575:Pesticides / Q000032:analysis*; D010782:Photolysis
chemical_list: D002247:Carbon Isotopes; D004785:Environmental Pollutants; D010575:Pesticides; C002302:dimethoxon; D004006:Dichlorvos; D004117:Dimethoate
keywords: CSIA; Dichlorvos; Dimethoate; Omethoate; Organophosphorus pesticides