凝胶渗透色谱-气相色谱-质谱联用快速测定大豆中克百威、乙草胺、甲草胺、异丙甲草胺、氟乐灵的残留量

建立了气相色谱-质谱（GC/MS）法，电子轰击离子化（EI）法同时测定及确证大豆中克百威、乙草胺、甲草胺、异丙甲草胺、氟乐灵的残留量。试样经乙腈提取，共提物中的色素和油脂用凝胶色谱（GPC）净化去除。采用GC/MS-SIM法对克百威、乙草胺、甲草胺、异丙甲草胺、氟乐灵进行定性和定量分析。结果表明，采用GPC净化，并设定收集时间在5~15 min内，能够有效避免大豆中油脂峰干扰，缩短分析时间。5种农药的加标回收率为66.6%～104.9%，测定的相对标准偏差为2.2%～12.3%。5种农药在0.01～0.1 mg/L范围内具有较好的线性，相关系数达0.996以上，方法中克百威、乙草胺、甲草胺、异丙甲草胺、氟乐灵的定量限均为0.01 mg/kg。

Determination of Residues of Carbofuran,Acetochlor,Alachlor,Metolachlor and Trifluralin in Soybean by GC / MS-GPC

Carbofuran,acetochlor,alachlor,metolachlor and trifluralin in soybean were determined by gas chromatography-mass spectrometry(GC/MS) with electron impact(EI) ionization.The soybean samples were extracted with acetonitrile.The pigment and lipin were cleaned up with GPC.Carbofuran,acetochlor,alachlor,metolachlor and trifluralin were analyzed by GC/MS with selected-ion monitoring(SIM).The results showed that GPC purification could avoid the influence of lipid collected time between 5 and 15 min.The recoveries of those pesticides are ranged from 66.2% to 104.9%,and standard deviations are from 2.2% to 12.3%.Under the optimized conditions,the calibration curves of 5 pesticides are linear in the range of 0.01—0.1 mg/L with correlation coefficients more than 0.996.The limits of quantitation of carbofuran,acetochlor,alachlor,metolachlor and trifluralin are 0.01 mg/kg.