高效液相色谱-串联质谱法检测粮食中辛硫磷残留量

Determination of Phoxim Residues in Grains by High Performance Liquid Chromatography- Tandem Mass Spectrometry

本文建立了高效液相色谱-串联质谱法测定粮食中辛硫磷农药的分析方法。粮食样品用乙酸乙酯提取,N-丙基乙二胺(PSA)固相萃取填料净化,Agilent Zorbax SB-C18色谱柱分离,以甲醇和5 mmol/L乙酸铵水溶液(含0.1%甲酸)为流动相梯度洗脱,采用电喷雾正离子(ESI+)源多反应监测模式(MRM)进行监测分析,外标法定量。目标物在5.0~250.0μg/L浓度范围内线性关系良好,相关系数(R^(2))为0.9998,方法的检出限为0.5μg/kg,定量限为2.0μg/kg,在2.0、10.0、20.0μg/kg 3个浓度加标水平下,辛硫磷回收率为82.2%~88.9%,相对标准偏差为4.6%~9.3%,方法操作简单、快速、重复性好、灵敏度高,适用于粮食中辛硫磷残留量的测定。

A method was developed for the determination of phoxim residues in grains by high performance liquid chromatography-tandem mass spectrometry.The samples were extracted with ethyl acetate,purified by dispersive solid phase extraction with primary secondary amine(PSA),and separated on Agilent Zorbax SB-C18 column with gradient eluted using methanol and 5 mmol/L ammonium acetate solution(containing 0.1%(V/V) formic acid)as mobile phases.The target compound was detected by electrospray ionization(ESI)positive mode under multiple reaction monitoring modes and quantified by external standard method.The linear range for the compound ranged from 5.0 μg/L to 250.0 μg/L,and the correlation coefficient(r^(2)) was 0.9998.The limit of detection(LOD) and limit of quantitation(LOQ) were 0.5 μg/kg and 2.0 μg/kg.At the spiked levels of 2.0,10.0,20.0 μg/kg,the recoveries ranged from 82.2% to 88.9% and the relative standard deviations(RSD) were between 4.6% and 9.3%.The method with good reproducibility and high sensitivity,is simple,rapid,and suitable for the determination of phoxim residues in grains.