搅拌棒吸附子萃取与GC-MS法测定水中20种有机氯农药

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(30 m×0.25 mm×0.25 μm)石英毛细管色谱柱为分析柱,气相色谱-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 ～20.0 μg/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 ～0.118 μg/L,水样中分别添加2.5、20 μg/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.

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

A new method for the simultaneous determination of 20 organochlorine pesticides, inclu-ding α-BHC, γ-BHC, β3-BHC, heptachlor, δ-BHC, aldrin, heptachlor epoxide, γ-chlordane, cis-chlordane, endosulfan I , p, p'-DDE, dieldrin, endrin, p, p'-DDD, endosulfan Ⅱ , p, p'-DDT, endrin hexadrin, endosulfan sulfate, methoxychlor and endrin ketone in water samples was developed by stir bar sorptive extraction (SBSE) coupled with gas chromatography - mass spectrome-try (GC - MS). The samples was extracted by stir bar and desorbed by methanol. The analytes were separated on a J & W DB-35 MS(30 m × 0. 25 mm × 0. 25 μm) column, and detected by GC - MS un-der 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 organochlorine 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.