搅拌棒吸附子萃取与GC-MS法测定水中20种有机氯农药

Determination of 20 Pesticides in Water Sample by GC-MS with Stir Bar Sorptive Extraction

建立了搅拌棒吸附子萃取／气相色谱-质谱法（SBSE／GC—MS）同时检测水中α-六六六、γ-六六六、β-六六六、七氯、δ-六六六、艾氏剂、环氧七氯、γ-氯丹、顺-氯丹、硫丹Ⅰ、p，p＇-滴滴伊、狄氏剂、异狄氏剂、p，p’-滴滴滴、硫丹Ⅱ、p，p＇-滴滴涕、异狄氏剂醛、硫丹硫酸盐、甲氧滴滴涕、异狄氏剂酮20种有机氯农药含量的方法。样品在室温下经拌棒吸附子搅拌吸附，甲醇解吸附后，以J＆W DB-35、MS（30m×0．25mm×0．25μm）石英毛细管色谱柱为分析柱，气相色谱一质谱选择离子流模式检测。考察了萃取时间、氯化钠及甲醇加入量等对萃取的影响。实验结果表明：在2．5～20．0μg,／L范围内，20种有机氯农药呈良好的线性关系，检出限（S／N=3）为0．008—0．118μg/L，水样中分别添加2．5、20μg／L的20种有机氯农药，回收率为52％～117％，相对标准偏差小于13％（n=6）。该方法操作简便、快速、灵敏度高，应用于实际样品检测，结果满意。

A new method for the simultaneous determination of 20 organochlorine pesticides, including α-BHC, γ-BHC, β-BHC, heptachlor, δ-BHC, aldrin, heptaehlor epoxide, T-chlordane, cis-ehlordane, endosulfan Ⅰ , p, p＇-DDE, dieldrin, endrin, p, p＇-DDD, endosulfan Ⅱ, p, p＇- DDT, endrin hexadrin, endosulfan sulfate, methoxyehlor and endrin ketone in water samples was developed by stir bar sorptive extraction （SBSE） coupled with gas chromatography - mass spectrometry （GC - MS）. The samples was extracted by stir bar and desorbed by methanol. The analytes were separated on a J＆W DB-35 MS（30m×0.25mm×0.25μm）column, and detected by GC -MS under selected ion monitoring （SIM） mode. Effects of extraction time, addition of salt and methanol on extraction efficiency were studied. The calibration curves showed a good linearity between 2.5 μg/L and 20 μg/L for 20 organochlorine pesticides. The limits of detection（ S/N= 3 ） ranged from 0. 008 μg/L to 0. 118 μg/L. The average recoveries of 20 organoehlorine pesticides in water sample at two spiked concentration levels of 2.5, 20 μg/L ranged from 52% to 117% with RSDs less than 13% （n = 6）. The method was rapid, simple, sensitive, and was applied to determine the real water with satisfactory results.