高效液相色谱串联质谱法测定蔬果中啶酰菌胺和环酰菌胺残留

建立蔬菜和水果中啶酰菌胺和环酰菌胺的高效液相色谱串联质谱检测方法。将试样中残留的啶酰菌胺和环酰菌胺用含1%乙酸的乙腈溶液均质提取,提取液混合使用乙二胺-N-丙基硅烷和十八烷基硅烷键合相基质分散净化,用高效液相色谱串联质谱检测和确证,外标法定量;方法通过空白基质溶液稀释标准建立校正的标准曲线,以消除基质效应。结果表明：啶酰菌胺和环酰菌胺在1～100μg/L范围内具有良好的线性关系,相关系数分别为0.9996和0.9997;在5～50μg/kg范围内,平均添加回收率在77.7%～93.8%之间,相对标准偏差在2.1%～6.3%之间。啶酰菌胺和环酰菌胺方法定量限分别为1.32μg/kg和1.20μg/kg,检出限分别为0.395μg/kg和0.361μg/kg。     

黄瓜与西葫芦中环酰菌胺的残留分析

[目的]建立环酰菌胺在黄瓜与西葫芦中的残留分析方法。[方法]样品用乙腈匀浆提取,全自动固相萃取仪硅胶柱净化,液相色谱-串联质谱检测。[结果]黄瓜和西葫芦中的添加回收率分别为86.6%~87.2%、89.4%~90.3%,变异系数分别为3.5%~4.3%、5.2%~6.6%,仪器最小检出量为1.0×10-11g,方法最小检出质量分数为0.05 mg/kg。[结论]该方法简单可靠,符合农药残留分析要求,可用于黄瓜和西葫芦中环酰菌胺的残留检测。     

Residues of azoxystrobin, fenhexamid and pyrimethanil in strawberry following field treatments and the effect of domestic washing

Residues of the pesticides azoxystrobin, fenhexamid and pyrimethanil were determined in strawberry after field treatment. The effect of 'home' washing with tap water and a commercially available vegetable detergent on residue levels was also studied. After treatment, azoxystrobin and pyrimethanil residues on strawberry were on average 0.55 and 2.98 mg kg^-1, respectively, values below the maximum residue level (MRL) fixed by the European Union (2.0 and 5 mg kg^-1, respectively), while fenhexamid residues were on average 2.99 mg kg^-1, which is very close to the MRL of 3.0 mg kg^-1, but some samples were over the MRL. Thereafter, all residues declined, with a half-life of about 8 days (azoxystrobin and fenhexamid) and 4.8 days (pyrimethanil). Washing the fruit with tap water reduced the residues of azoxystrobin and fenhexamid but did not affect pyrimethanil residues. Finally, when fruits were washed with a commercial detergent, greater amounts were removed (about 45% of azoxystrobin and pyrimethanil and 60% of fenhexamid).     

环酰菌胺的合成

以(2,3-二氯-4-羟基苯基)偶氮苯为原料,制备了2,3-二氯-4-羟基苯胺,收率为90%;然后与1-甲基环己基甲酰氯反应制备标题化合物环酰菌胺,此步反应收率达92.4%.两步反应总收率为83.2%.