采用气相色谱法测定反季节蔬菜豇豆和苦瓜中毒死蜱、除尽、联苯菊酯、功夫菊酯和氯氰菊酯等5种农药残留量。样品经乙腈提取后,所得豇豆提取液经0.22 μm滤膜过滤,所得苦瓜提取液经Agela Cleanert PestiCarb-SPE固相萃取柱净化。在DB-1毛细管色谱柱上,5种农药达到很好分离。5种农药的线性范围均为0.01~5.0 mg·L-1。方法用于测定豇豆和苦瓜中5种农药的残留量,并在2个不同浓度水平下进行了回收和精密度试验,所得回收率在64.7%~98.8%之间,相对标准偏差(n=6)小于9.0%。

Gas chromatography was applied to the determinations of residual amounts of 5 pesticides (i.e., chlorpyrifos, chlorfenapyr, bifenthrin, cyhalothrin and cis-cypermethrin) in 2 off-season vegetables (cowpea and bitter gourd). The sample was extracted with acetonitrile, the extract of cowpea obtained was filtered with 0.22 μm membrane and the extract of bitter gourd obtained was purified by Agela Cleanert PestiCarb-SPE solid phase column. By using DB-1 capillary chromatographic column, the 5 pesticides were separated completely. Linearity ranges of 5 pesticides were kept in the same range of 0.01-5.0 mg·L-1. The proposed method was used in the determination of 5 pesticides in substantial samples. Tests for recovery and precision were made by standard addition method at 2 different concentration levels, values of recovery found were in the range of 64.7%-98.8% and values of RSD′s (n=6) were less than 9.0%.