气相色谱法测定水产品中有机磷的残留量

建立了水产品中甲胺磷、乙酰甲胺磷、敌敌畏、乐果、对硫磷、甲基对硫磷、马拉硫磷7种有机磷农药残留量的测定方法.样品用正己烷配合乙腈均质提取,经凝胶柱净化后进行气相色谱(GC)分析,采用外标法定量.优化条件下该方法的定量限(S/N=10):甲胺磷为0.0083 mg.kg-1,敌敌畏为0.011 mg.kg-1,乙酰甲胺磷为0.020 mg.kg-1,乐果为0.039 mg.kg-1,甲基对硫磷为0.063 mg.kg-1,马拉硫磷为0.055 mg.kg-1,对硫磷为0.031 mg.kg-1.在加标水平为0.0667、0.333和1.67 mg.kg-1时,7个组分的回收率为74.4%-108%,相对标准偏差为2.06%-6.98%(n=6).

Determination of organophosphate residues in aquatic product by the method of gas chromatography

Seven organophosphate residues(methamidophos,dichlorvos,acephate,dimethoate,parathion-methyl,malathion,parathion-ethyl) in aquatic product were determined by the method of gas chromatography.Organophosphate residues were first extracted from homogenized sample with acetonitrile-water assisted by n-hexane,after purification with gel filtration column,the separation and determination of organophosphate analytes were performed by the method of capillary GC and external standard calibration.Under the optimization conditions,the detection limits(S/N=10) of methamidophos,dichlorvos,acephate,dimethoate,parathion-methyl,malathion,parathion-ethyl were 0.0083,0.011,0.020,0.039,0.063,0.055 and 0.031 mg·kg-1,respectively.The standard addition recoveries of organophosphate at the level of 0.0667,0.333,1.67 mg·kg-1 ranged from 74.4% to 108%,and the relative standard derivation ranged from 2.06% to 6.98%.