GC-NCI-MS分析粮谷中多类农药残留

 建立了粮谷中14种农药残留（9种有机氯、3种拟除虫菊酯和2种含氯有机氮）气相色谱-负化学源-质谱（GC-NCI-MS）的分析方法，试样样品用V(正己烷)∶V(丙酮)=1∶1超声波提取，硅镁吸附剂净化，采用GC-NCI-MS选择离子扫描方式检测.结果表明，该方法准确、快速、选择性好、抗干扰能力强，14种农药的方法最低检出限：0.01～0.18?μg/kg，平均添加回收率在75.2%～109.7%之间，变异系数都小于10%，并成功应用于大米、面粉试样中痕量农药残留分析.

Multiresidue determination in grain by gas chromatography-negative chemical ionization-mass spectrometry

A simultaneous determination of 14 pesticides (9 organochlorines,3 py rethroid and 2 organonitrogen) in grain was developed.Pesticides were extracted from sample with 1:1 hexane-acetone in an ultrasonic bath and were purified on a Florisil column,then were determined by gas chromatography with negative chem ical ionization mass spectrometer,using ion monitoring mode.The method was acc urate ，covenient，sensitive and selective. The detection limit of the method w as 0.01—0.18?μg/kg,the average recoveries ranged from 75.2% to 109.7%,while t he relative standard deviations were less then 10%.The analytical method was su ccessfully applied to determine pesticides in several grain samples.