Compound specific isotope analysis of organophosphorus pesticides.
Compound specific isotope analysis of organophosphorus pesticides.
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DOI：
10.1016/j.chemosphere.2014.04.037
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发表时间：
2014-09
期刊：
影响因子：
8.8
通讯作者：
Langping Wu;Jun Yao;P. Trebše;Ning Zhang;H. Richnow
中科院分区：
文献类型：
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作者：
Langping Wu;Jun Yao;P. Trebše;Ning Zhang;H. Richnow
化合物特定同位素分析(CSIA)已被建立为一种研究各种污染物的环境归宿的工具。在这项研究中，建立了CSIA来分析广泛使用的有机磷农药：敌敌畏、氧乐果和乐果的稳定碳同位素特征。对目标农药进行了GC-C-IRMS系统的线性测试，并在仪器的不确定度范围内获得了可接受的同位素组成。为了评价方法的准确性，研究了蒸发过程对碳同位素组成(δ~(13)C)测定值的影响，结果表明，溶剂蒸发浓缩没有显著的同位素效应。然后，CSIA被应用于研究选定农药的水解和光解的同位素分馏。用瑞利模型定量测定了供试农药的碳同位素分馏系数，其中敌敌畏的体富集系数(ε)为0.20±100.1‰，乐果的体富集系数(−)为1.00±0.10‰，乐果光解的体富集系数(BET)为3.7g±11.1‰。这项研究是将CSIA应用于追踪有机磷农药在环境中的迁移和降解的第一步。
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 (δ13C) 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.