SPME-GC-ECD法测定含硫蔬菜中的有机氯农药

Determination of organochlorine pesticides in sulfur-containing vegetables with SPME-GC-ECD

建立了顶空固相微萃取(HS-SPME)与气相色谱-电子捕获检测器(GC-ECD)联用测定含硫蔬菜中有机氯农药(OCPs)的方法。该方法采用的是自制的三苄基杯[6]芳烃/羟基硅油(Benzyl-C[6]/OH-TSO)探头,该探头具有耐高温、使用寿命长等特点。采用10%磷酸处理含硫蔬菜,使其中的酶失去活性,避免产生干扰的硫化物影响有机氯农药的测定。为了得到最佳的萃取效果,对影响涂层萃取效率的条件进行了优化。该方法的检测限为0. 10~1. 8 ng·L^(-1),重现性好(RSD<12. 3%),线性范围宽(2~3个数量级),准确度高,回收率在83. 2%~107%之间。实验结果表明该方法适合于含硫蔬菜中痕量OCPs的分析检测。

Benzyl-calix[6]arene/hydroxyl-terminated silicone oil(C[6]/OH-TSO)was used with headspace solid-phase microextraction(HS-SPME)combined with gas chromatography(GC)and electron capture detection(ECD),which was applied to determine seven organochlorine pesticides(OCPs)in sulphur-containing vegetables(green Chinese onion,garlic,onion,garlic pedicel and leek,etc).These vegetables were treated with 10%phosphoric acid solution to inactivate enzymes.Various parameters affecting the extraction efficiency were optimized to maximize the sensitivity during the OCPs analysis.Under optimal conditions,linear ranges of the method were two or three orders of magnitude and limits of detection(S/N=3)ranged between 0.10 to 1.8 ng·L^-1.The relative standard deviation(n=5)values obtained were less than 12.3%.The recoveries of OCPs in garlic sample were from 83.2%to 107%.