室温及低温制备生菜样本过程的不确定度和25种农药残留的稳定性

以毒死蜱为内标,对农药残留分析中生菜样本的两种制备方法——室温处理和低温加干冰处理结果的不确定度进行了比较研究;进一步采用统计学t-检验,对25种农药在两种制备方法中的稳定性进行了评价。采用QuEChERS(quick,easy,cheap,effective,rugged,safe)方法对处理后样本进行提取、净化,以乙腈为提取剂,N-丙基乙二胺键合固相吸附材料PSA(primary secondary amine)为分散净化剂,采用GC-MS方法分析。结果显示,两种制备方法结果的不确定度接近(室温5.2%,低温5.4%);低温处理过程会提高某些农药的稳定性,降低分解率,如甲萘威和残杀威在低温处理时稳定性明显提高,而敌敌畏和百菌清则在两种处理条件下都会分解。表明农药的稳定性既与农药本身的理化性质有关,也受处理过程中的操作条件等影响。

Testing the Uncertainty and 25 Kinds of Pesticide Residue Stability in Ambient and Cryogenic Processing of Lettuce Sample

Taken chlorpyrifos as internal standard,the uncertainty during the ambient and cryogenic processing of lettuce matrix was estimated,and t-test was applied to compare the stability of 25 kinds of pesticide during two sample processing methods,and then QuEChERS method was used in which acetonitrile was as extraction solvent,primary secondary amine (PSA) as sorbent,and pesticides were detected by gas chromatography-mass spectrometer (GC-MS).The results showed that the uncertainty was not significant different ...