QuEChERS-气相色谱-质谱法同时测定香蕉酸奶中5种拟除虫菊酯类农药残留

Determination of 5 pyrethroid pesticides in banana yogurt by QuEChERS-gas chromatography-mass spectrometry

样品经乙腈提取、无水MgSO_4除水后,提取液用N-丙基乙二胺(PSA)和十八烷基键合硅胶(C_(18))净化,上清液氮吹至近干后用正己烷复溶,经Agilent HP-5色谱柱分离,采用质谱在选择离子模式下测定。结果表明:各组分在质量浓度为0.05～3.00 mg/L之间呈现良好的线性关系,相关系数均在0.9980以上;该方法的检出限在0.60～1.83μg/kg之间;在质量浓度为0.20,0.75和1.00 mg/L 3个加标水平下,5种拟除虫菊酯类农药的回收率在82.5%～104.3%之间,相对标准偏差为3.1%～6.4%,能够满足香蕉酸奶中5种拟除虫菊酯类农药的测定需求。

The sample was extracted by acetonitrile, dehydrated by anhydrous MgSO4, and cleaned up by primary secondary amine （PSA） with octadecyl bonded silica gel （C1,）. Supernate was blown to approximated dry by N2 and then dissolved by hexane. Agilent HP-5 column was used for seperation, and target compounds were determined by mass spectrometry in selected ion mode. The results showed that the linear range of the method between 0.05～3.00 mg/L was favorable, and the correlation coefficients were more than 0.9980, with the detection lim- its were in the range of 0.60～1.83 μg/kg. The averang recoveries of 5 pyrethroid pesticides at three spiked concentration level （0.20, 0.75 and 1.00 mg/L） varied from 82.5% to 104.3%, with the relative standard deviations ranged from 3.1% to 6.4%. The results could satisfy the requirement of 5 pyrethroid pesticides residue analysis in banana yogurt.