烟草中6种二硝基苯胺类农药残留量的测定

Determination of Residues of Six 2,6-Dinitroaniline Pesticides in Tobacco

为提高烟草中二硝基苯胺类农药残留的检测效率,建立了一种以"灭蚁灵"为内标,正己烷作萃取剂,加速溶剂萃取(ASE)和气相色谱(配ECD检测器)测定烟草及烟草制品中"止芽素"、"氟节胺"、"异丙乐灵"、"二甲戊灵"、"乙丁氟灵"和"氟乐灵"等6种2,6-二硝基苯胺类农药残留量的方法,并采用该方法测定了100个卷烟和烟叶样品的残留量。结果表明:①方法的回收率在90.0%～98.1%之间,RSD均小于7%,检测限在0.003～0.006μg/g之间;②10个烟叶和22个卷烟样品中未检出任何二硝基苯胺类农药,分别占所选烟叶和卷烟样品数的20%和44%,其它样品都或多或少地残留有二硝基苯胺类农药,但残留量均低于CORESTA指导性残留限量(GRLs);③在所测定的样品中,"氟节胺"、"二甲戊灵"、"止芽素"、"异丙乐灵"、"乙丁氟灵"和"氟乐灵"的检出率分别为45%,30%,8%,3%,1%和1%;④国产和进口卷烟样品中检出有二硝基苯胺类农药残留的分别为7个和21个。进口和国产卷烟样品中检出的主要农药分别是"氟节胺"和"二甲戊灵";⑤进口烟叶样品中均检出有二硝基苯胺类农药残留,且6种二硝基苯胺类农药均有检出。其中,"氟节胺"、"二甲戊灵"和"止芽素"的检出率分别为48%,32%和20%,其它3种二硝基苯胺类农药的检出率均小于10%;⑥15个国产烟叶样品中检出二硝基苯胺类农药残留,检出率60%。其中,"氟节胺"、"二甲戊灵"和"异丙乐灵"的检出率分别为40%,32%和4%,其它3种二硝基苯胺类农药均未检出。

In order to accelerate the detection of 2, 6 - dinitroaniline pesticide residues in tobacco, a method for determining the residues of 2, 6 -dinitroaniline pesticides, including flumetralin, pendimethalin, butralin, isopropalin, benfluralin and trifluralin, in tobacco and tobacco products by accelerate solvent extraction （ASE） with florisil and n-hexane as extracting solvent and gas chromatography with an electron capture detector using mirex as an internal standard was developed, and 100 samples of cigarette and tobacco leaf were tested. The results showed that ： 1 ） The recoveries of the pesticides ranged from 90.0% to 98.1% with the RSDs of below 7.0% and the limit of detection of 0. 003 to 0. 006 μg/g. 2） 2, 6 - Dinitroaniline pesticide residues were not detectable in 10 leaf samples and 22 cigarette samples, which accounted for 20% and 44% of leaf samples and cigarette samples, respectively; the pesticide residues were more or less detectable in the other samples, however which were lower than the guidance residue levels recommended by CORESTA. 3 ） The detection rates of flumetralin, pendimethalin, butralin, isopropalin, benfluralin and trifluralin were 45% , 30% , 8% , 3% , 1% and 1% , respectively. 4） The pesticide residues were detected in 7 domestic cigarette samples and 21 imported cigarette samples, in which flumetralin and pendimethalin were the main residues in imported and domestic cigarette samples, respectively. 5 ） All of six 2, 6 - dinitroaniline pesticide residues were detected in imported tobacco leaf samples, in which the detection rates of flumetralin, pendimethalin, butralin, isopropalin, benfluralin and trifluralin were 48%, 32%, 20%, 8%, 4% and 4% , respectively. 6） Three of the 2,6 - dinitroaniline pesticide residues were detected in 15 domestic leaf samples, which accounted for 60% of domestic leaf samples, the detection rates of flumetralin, pendimethalin and isopropalin were 40% , 32% , and 4% , respectively.