地质调查样品中有机氯农药分析存在的困难和解决方法

9种有机氯农药(六氯苯、α-HCH、β-HCH、γ-HCH、δ-HCH、p,p′-DDE、p,p′-DDD、o,p′-DDT和p,p′-DDT)是国土资源地质大调查项目中水和土壤样品必测的有机污染物。有机氯农药自身结构和性质的特殊性以及地质调查样品的差异性,在采用气相色谱电子捕获检测器(GC-ECD)分析有机氯农药过程中仍然存在许多困难。文章结合大量地质调查样品中有机氯农药分析的实践经验,从溶剂与待测物响应值的关系、基质效应的表现、样品前处理以及仪器日常维护四个方面,介绍了针对不同样品和分析要求正确选择进样溶剂、判断和解决基质效应,并通过良好的仪器日常维护习惯确保地质调查样品中有机氯农药检测灵敏度达到要求。

Problems and Solutions in the Determination of Organochlorine Pesticides in Geological Survey Samples

Nine organochlorine pesticides(HCB,α-HCH,β-HCH,γ-HCH,δ-HCH,p,p′-DDE,p,p′-DDD,o,p′-DDT and p,p′-DDT)in water and soil samples are the priority pollutants to be determined in geological survey project.There are some analytical problems from complex sample matrix and some special properties of these pollutants when gas chromatography with electron capture detector was used.Based on the experiences in analysis of thousands of survey samples,how to diagnose and solve the problems were discussed from following four aspects:1) the relationship between solvent and analyte response,2) sample matrix effect,3) sample pretreatment,4) instrument measurement.These experiences will help analysts to solve the analytical problems and obtain reliable analytical data.