2,2-双(对氯苯基)-1-氯乙烯稳定氯同位素组成测定的氧化脱氯前处理方法  

Study on the oxidation dechlorination reaction for determination of chlorine isotopic composition of 1,1-dichloro-2,2-bis(4-chorophenyl)ethylene

作　　者：张亚男[1] 田芹[2] 宋淑玲[2,3] 

机构地区：[1]中国地质大学(武汉),生物地质与环境地质国家重点实验室,地球科学学院/环境学院,武汉430074 [2]中国地质科学院国家地质实验测试中心,北京100037 [3]中国地质科学院地球物理地球化学勘查研究所,河北廊坊065000

出　　处：《农药学学报》2016年第6期772-777,共6页Chinese Journal of Pesticide Science

基　　金：国家自然科学基金(41473008,21307018);中国地质科学院院基金(YWF201402)

摘　　要：2,2-双(对氯苯基)-1-氯乙烯又称p,p′-DDE,是农药p,p′-DDT重要的一级降解产物,在环境中广泛存在,对哺乳动物具有显著的雄性激素受体干扰效应。p,p′-DDE的稳定氯同位素δ^(37)Cl值的测定可用于环境中化合物的示踪及迁移转化研究。本文报道了采用离子色谱法测定Cl–产率和Gas Bench-IRMS离线法测定p,p′-DDEδ^(37)Cl值的氧化脱氯反应条件的优化,确定了最佳氧化脱氯反应条件。以Cu O为氧化剂,通过氧化脱氯反应将p,p′-DDE中的有机态氯转换为Cl–,比较了真空度、不同反应温度和不同反应时间对Cl–产率和δ^(37)Cl_(product) SOMC/‰值的影响。结果表明:在真空环境下,当p,p′-DDE与足量CuO反应时,δ^(37)Cl_(product) SOMC/‰值与Cl–产率在500~720℃范围内满足线性方程y=1.44x–4.41,R^2为0.96。且在720℃、反应1 h的条件下,p,p′-DDEδ^(37)Cl值的测定误差最小,在±0.15‰以内。1,1-dichloro-2,2-bis（4-chorophenyl）ethylene（p,p＇-DDE） is the primary metabolite of 1,1＇-（2,2,2-trichloroethane-1,1-diyl）bis（4-chlorobenzene） which is a pesticide. p,p＇-DDE was ubiquitous in the environment, and has significant interference effect on the male hormone receptor in the mammal.The chlorine isotopic composition（δ^37l） of p,p＇-DDE can be used to study the fate of the compound in environment. In order to obtain the optimal reaction conditions, the Cu O catalysed oxidative dechlorination reaction of p,p＇-DDE were conducted under vacuum, different temperatures（520-900 ℃）and time（0.5-1.0 h）. Cl– formed in the reaction was determined by ion chromatography and the δ^37lwas determined by Gas Bench-IRMS. The experimental results showed there is a linear dependence between δ^37l_（product） SOMC/‰ and yield of Cl– when p,p＇-DDE reacted with enough Cu O at 520 ℃ to720 ℃ under vacuum condition. The linear equation was y=1.44x–4.41 with 0.96 for R2. Besides, the error value of δ^37l_product SOMC/‰ for p,p＇-DDE was lower than ±0.15 ‰ when the reaction conditions were 720 ℃ and 1h. In conclusion, a more effective and accurate preparative method was developed for the determination of δ^37lproduct SOMC/‰ of semi-volatility organo-chlorine compounds.

关 键 词：2 2-双(对氯苯基)-1-氯乙烯 稳定氯同位素 氧化脱氯反应 含氯半挥发性有机物 

分 类 号：X839.2[环境科学与工程—环境工程] P597.2[天文地球—地球化学]