生姜中8种酰胺类除草剂残留的分析方法

Simultaneous determination of residues of eight amide herbicides in fresh ginger

建立了同时测定生姜中8种酰胺类除草剂(炔苯酰草胺、敌稗、乙草胺、异丙甲草胺、甲草胺、丁草胺、丙草胺、苯噻草胺)残留的气相色谱(GC-ECD)分析方法。样品经乙酸乙酯超声提取(加入少量氢氧化钠溶液调节pH值至7),乙二胺-N-丙基硅烷(PSA)净化,气相色谱检测。结果表明:在0.01～1 mg/L范围内,8种除草剂的线性相关系数均大于0.995,检出限(LOD)为4～10μg/kg,定量限(LOQ)为0.05 mg/kg;在0.05、0.1和1 mg/kg 3个添加水平下的平均回收率在79.0%～111.2%之间,相对标准偏差(RSD)为0.9%～11.5%。

An analytical method for the simultaneous determination of residues of 8 amide herbicides （ propyzamide, propanil, acetochlor, metolachlor, alachlor, butachlor, pretilachlor, mefenacet ） in fresh ginger using gas chromatography with electron capture detector （GC-ECD） was developed. The samples were extracted with ethyl acetate by ultrasonic, pH was adjusted to 7 with NaOH solution for reducing interference and further clean-up was carried out by primary secondary amine. It showed that good linearity was obtained between 0.01 and 1 mg/L with correlation coefficients above 0. 995. The limits of detection were 4 - 10 μg/kg and the limits of quantification were 0.05 mg/kg. Fortified recoveries at 0.05,0. 1 and 1 mg/kg were between 79.0% and 111.2% with the relative standard deviations （RSD） from 0.9 % to 11.5 %, respectively.