土壤样品多氯联苯的GC/ECD双柱测定方法的优化

GC/ECD法是目前测定土壤样品多氯联苯（PCBs）总量最常用的方法.笔者参考US EPA 8082方法,针对实际土壤样品基质复杂、浓度差别大、有机氯农药干扰GC/ECD测定等特点,对样品前处理和仪器分析的各个环节进行了系统的试验研究.采用碱解萃取、酸洗、硅胶柱净化、双柱GC/ECD分析方法,将多元线性回归分析用于混合Aroclor污染类型的定性识别,外标法用于PCBs总量的定量分析.PCBs总量的清洁基体加标回收率为80%～90%,方法检出限为0.40 ng/g. 

Optimization of the Analytical Method for Polychlorinated Biphenyls in Soil Samples by Dual-Column GC/ECD

The GC/ECD method for the determination of total polychlorinated biphenyls （PCBs） in soil samples has been widely used　presently.Due to the complex matrix,large concentration ranges,and interferences from organochlorine pesticides in real soil samples,the present study attempts to optimize the sample pretreatment and instrumental analysis procedures of PCBs in soils.On the basis of US EPA method 8082,alkali Soxhlet extraction,clean up by acid wash and silica column,and dual-column GC/ECD analysis were employed in this study.Furthermore,multiple linear regression analysis was used for qualitatively identifying samples contaminated by Aroclor mixture,and external standard method was used for quantitatively analyzing total PCBs.The recoveries for total PCBs ranged from 80% to 90% based on the clean matrix spiked test.Method detection limit was 0.40 ng/g for the total PCBs.