QuEChERS EMR-Lipid净化结合超高效液相色谱-串联质谱法测定牛奶中阿维菌素类药物残留量

Determination of avermectins residues in milk by ultra high performance liquid chromatography-tandem mass spectrometry coupled with QuEChERS EMR-Lipid

建立了以QuEChERS EMR-Lipid净化为前处理方法,结合超高效液相色谱-串联质谱测定牛奶中阿维菌素类药物残留量。采用乙腈提取牛奶样品中残留的阿维菌素类药物,盐析分层,上清液经EMR-Lipid净化,Phenomenex Kinetex C18色谱柱进行分离,以0.1%甲酸水溶液和甲醇为流动相进行梯度洗脱,质谱法在正离子模式下以多反应监测方式监测,基质匹配法外标定量。结果表明4种阿维菌素类药物质量浓度在0.5~20μg/L范围内线性良好,相关系数(r)>0.998,定量限为0.071~0.280μg/kg,平均回收率在96.6%~108.8%之间,相对标准偏差(RSD)为0.98%~4.75%。该法前处理步骤简便,净化效果良好,提高检品检测效率,适用于大批量牛奶样品中阿维菌素类药物的检测。

A QuEChERS EMR-Lipid pretreatment method for determination of avermectins residues in milk was established by ultra high performance liquid chromatography-tandem mass spectrometry.The avermectins residues in milk were extracted by acetonitrile.After salting-out,the supernatant was cleaned-up by EMR-Lipid.Separation of the analyte was carried out on a PhenomenexKinetex C18 column by gradient elution with 0.1%formic acid and methanol.The avermectins residues were detected by multiple reaction monitoring(MRM)with electrospray ionization(ESI)under positive ion mode.The target compounds were quantified by the matrix-matched external standard method.The mass concentration of four avermectins had a good linear relationship in the range from 0.5 to 20μg/L with correlation coefficients(r)more than 0.998,and the quantitative limits were 0.071-0.280μg/kg.The recoveries of avermectins were in the range of 96.6%-108.8%,and the relative standard deviations were 0.98%-4.75%.The method has the merits of simple pretreatment steps and good purification effect.It improved sample detection efficiency.It was suitable for determination of avermectins in a large number of milk samples.