顶空溶剂吸收-气相色谱法对莴笋中代森锌残留量的测定

Determination of Zineb Residue in Asparagus Lettuce by Headspace Solvent Absorption-Gas Chromatography

采用顶空溶剂吸收-气相色谱法(配电子捕获检测器),以盐酸·氯化亚锡(Cl·Sn Cl2)为反应试剂,正己烷为吸收溶剂,以反应最终生成的二硫化碳测定值代表代森锌含量,建立莴笋中代森锌检测方法。分析莴笋不同部位代森锌的残留,探明其残留分布情况及消解规律。结果表明,该方法操作简便,色谱分析时间短,线性良好,检出限为0.10 mg/kg,代森锌平均转化率为90.4%~98.0%,平均回收率为82.8%~103.6%,相对标准偏差为2.4%~6.3%;莴笋中代森锌残留量表现为莴笋叶>带皮莴笋茎>去皮莴笋茎,施药14 d后,代森锌降解率均达到85%以上。

The reaction was carried out using a headspace-absorption GC-ECD,HCl·SnCl2 as the reaction reagent,n-hexane as the sorption solvent,determine the residue of zineb indicated by CS2,establish a method for the detection of zineb in asparagus lettuce.Analysis the residues in different parts of lettuceand to determine its residual distribution and its digestion.This method is simple,fast and has good linearity,the detectable limit is 0.10 mg/kg,the average conversion rate of zineb was 90.4%~98.0%,the average recovery was 82.8%~103.6%,relative standard deviation was 2.4%~6.3%.The residue of zineb in asparagus lettuce showed that leaves>stems>peeled stems,14 days after spraying,zineb digestion rate reached more than 85%.