采用气相色谱-串联质谱法测定生姜中25种农药的残留量。样品用乙腈提取,过NH2/Carbon固相萃取柱净化,将淋出液浓缩后用正己烷-丙酮(9+1)溶液定容。通过VF-5MS色谱柱分离,串联质谱测定。25种农药的质量浓度在0.020~0.500 mg·L-1范围内与其峰面积均呈线性关系,检出限(3S/N)在0.2~10.0 μg·kg-1之间。加入两个浓度水平的农药标准溶液进行了回收试验,多数农药的回收率在77%~130%之间,相对标准偏差(n=5)均小于20%。

Gas chromatography in hyphenation with tandem mass spectrometry (GC-MS/MS) was applied to the determination of residual amounts of 25 pesticides in ginger. The sample was extracted with acetonitrile, which was concentrated and purified by NH2/Carbon solid-phase extraction column. The eluate was evaporated to near dryness and diluted to a definite volume with mixture of n-hexane and acetone (9+1), and separated on the VF-5MS column. The eluate was used for tandem MS analysis. Linear relationships between values of peak area and mass concentration of the 25 pesticides were obtained in the same range of 0.020-0.500 mg·L-1, with detection limits (3S/N) in the range of 0.2-10.0 μg·kg-1. Test for recovery were made by addition of standard at 2 different concentration levels, values of recovery for most of the pesticides found were in the range of 77%-130%, with values of RSD′s (n=5) less than 20%.