中文摘要：

采用GC-C-IRMS、EA-IRMS和Dual-inlet IRMS 3种稳定同位素比值质谱仪分别对六六六的α、β和γ3种异构体的稳定碳同位素组成进行了分析。对比3种分析系统测定的碳同位素组成数据表明GC-C-IRMS系统能够准确和精确地测定六六六碳同位素组成。应用GC-C-IRMS技术分析了水样品中α-和γ-六六六的碳同位素组成，结果表明六六六在溶解、稀释、萃取，挥发等过程碳同位素组成没有分馏现象。采用GC—C—IRMS技术分析环境样品中持久性有机氯农药稳定碳同位素组成可能得到广泛应用。

英文摘要：

Recent studies suggest that compound-specific isotopic analysis of organic contaminants is a promising tool for environmental research. It is important to expand the database of isotopic characterizations for organic contaminants of interests. The stable carbon isotope values of α-, β-, and γ-hexa- chlorocyclohexane（HCH） isomers were determined by GC - C - IRMS, EA - IRMS, and Dual-inlet IRMS in this study. Comparison of the δ^13C values obtained from these three isotopic analytic systems indicated that the GC - C - IRMS method used in this study is sufficiently accurate and precise. The isotopic compositions of a- and γ-HCH in aqueous samples were monitored and the results suggest no isotope fractionation occurs during the course of dissolution, dilution, extraction and volatilization. Data provided in this study indicate that GC - C - IRMS may be an appropriate tool to study the isotopic compositions of the persistent organochlorine pesticides in environment.