固相萃取-液相色谱-串联质谱法测定中药材中7种甲氧基丙烯酸酯类杀菌剂的残留量

建立了采用固相萃取-液相色谱-串联质谱同时测定麦冬、玄参、延胡索中7种甲氧基丙烯酸酯类杀菌剂残留量的方法。样品经乙酸乙酯提取,氨基固相萃取柱净化后,经C18色谱柱分离,以甲醇和1.0‰甲酸溶液为流动相梯度洗脱,电喷雾正离子模式离子化,选择反应监测方式监测,串联质谱测定,外标法定量。结果显示,各目标物在1或2个数量级浓度范围内的线性关系良好,相关系数均大于0.996。醚菌胺、啶氧菌酯和肟菌酯的定量限为2 μg/kg,嘧菌酯和吡唑醚菌酯的定量限为4 μg/kg, Z-苯氧菌胺和醚菌酯的定量限为10 μg/kg。各杀菌剂的回收率为60.4%～110%,相对标准偏差为1.2%～17%。该方法能满足麦冬、玄参、延胡索中7种目标杀菌剂残留量的检测。

Determination of seven strobilurin fungicide residues in Chinese herbs by liquid chromatography-tandem mass spectrometry coupled with solid phase extraction

An LC-MS/MS method was developed for the simultaneously determination of seven strobilurin fungicide residues in Chinese herbs. The strobilurin fungicides include Z-metominostrobin, kresoxim-methyl, dimoxystrobin, picoxystrobin, pyraclostrobin, azoxystrobin and trifloxystrobin. The sample was extracted with ethyl acetate and cleaned-up by an amino SPE column. The seven strobilurin fungicide residues were separated on a C18 column with gradient elution of 1.0‰ formic acid and methanol as mobile phases, and detected by ESI-MS in positive ion and selective reaction monitoring （SRM） mode. External standard method was used to the quantification with good linear relationships （r≥0.996）. The LOQs were 2 μg/kg for dimoxystrobin, picoxystrobin and trifloxystrobin, 4 μg/kg for pyraclostrobin and azoxystrobin, 10 μg/kg for Z-metominostrobin and kresoxim-methyl. The recoveries were from 60.4% to 110% with the RSDs between 1.2% and 17%. The developed method is suitable for the determination and confirmation of the seven strobilurin fungicide residues in the three of Eight Zhes （Ophiopogon japonicus （Thunb.）, Scrophularia ningpoensis Hemsl. and Corydalis yanhusuo W T Wang）.