气相色谱-质谱法测定土壤中有机氯农药及多氯联苯

GC-MS Determination of Organochlorine Pesticides and Polychlorobiphenyls in Soil

提出了土壤中有机氯农药及多氯联苯的测定方法。土壤样品中22种以污染物存在的农药以丙酮-正己烷（1＋1）混合溶剂，用加速溶剂萃取仪进行提取，所得萃取液浓缩至1mL，通过固相萃取柱进行纯化。用正己烷-乙酸乙酯（8＋2）混合溶剂将农药从柱上洗脱，洗脱液浓缩至1mL后供气相色谱-质谱法测定，采用选择离子（SIM）模式。在两个浓度水平上加入各农药的标准进行了回收试验，测得回收率在68％～130％之间，测定值的相对标准偏差（n=6）均小于25．5％。测得22种农药的检出限（3s／b）在0．25～0．72ng·g^-1之间。

Twenty two organochlorine pesticides （OCP＇s）, including polyehlorobiphenyls （PCBP＇s）, present in soil as pollutants, were extracted from soil sample with mixed solvent of acetone and n-hexane （1 ＋ 1） by accelerated solvent extraction. The extract was concentrated to 1 mL, which was then purified on the solid phase extraction column and eluted from the column with mixed solvent of n-hexane and ethylacetate （8＋2）. The eluate was concentrated to 1 mL and used for GC-MS determination, with SIM mode. Recovery was tested by addition of standards of the 22 pesticides at 2 different concentration levels, and the results of recovery were found in the range of 68%-130%. Values of RSD＇s （n=6） found for all the 22 pesticides were less than 25. 5%. Detection limits （3s/b） found were in the range of 0. 25 to 0. 72 ng·g^-1.