液相色谱-串联质谱法测定果蔬中10种酰胺类农药的残留量

Determination of 10 amide pesticides in fruits and vegetables by liquid chromatography-tandem mass spectrometry

目的建立果蔬中甲草胺、乙草胺、异丙甲草胺、敌草胺、啶酰菌胺、环酰菌胺、甲霜灵、吡螨胺、唑虫酰胺和炔苯酰草胺残留量测定的液相色谱-串联质谱方法。方法样品经乙腈提取,固相萃取净化,采用C18色谱柱(150 mm×4.6 mm,3.5μm)分离,以0.1%甲酸-5 mmol/L乙酸铵混合溶液-甲醇为流动相,梯度洗脱,串联质谱测定,外标法定量。结果 10种酰胺类农药在2.0~50μg/L浓度范围内线性关系良好,相关系数均大于0.99,定量限均为0.01 mg/kg,方法的回收率范围为71%~98%,相对标准偏差均不大于9.5%。结论本方法可用于同时检测果蔬中10种酰胺类农药残留量。

Objective To establish a method for the determination of alachlor, acetochlor, metolachlor, napropamid, boscalid, fenhexamid, metalaxyl, tebufenpyrad, tolfenpyrad, and propyzamide in fruits and vegetables by liquid chromatography-tandem mass spectrometry. Methods Ten amide pesticides were extracted from samples with acetonitrile, cleaned up by solid-phase extraction, separated on a C18 column using 0.1% formic acid-5 mmol/L ammonium acetate solution-methanol as mobile phase, and then determined by tandem mass spectrometry. An external standard method was used for quantitative analysis. Results The calibration curves for all amide pesticides were linear in the range of 2.0~50 μg/L, the correlation coefficient was more than 0.99, and the limit of quantitation for all amide pesticides was 0.01 mg/kg. The recoveries were between 71% and 98% with relative standard deviations no more than 9.5%. Conclusion This method is suitable for the determination of 10 amide pesticides in fruits and vegetables at the same time.