UPLC-MS/MS测定生乳与豆制饮品中咪唑烟酸残留

Determination of imazapyr residues in raw milk and soybean drinks by UPLC-MS/MS

该研究考察生乳与豆制饮品中咪唑烟酸的前处理条件,旨在建立一种超高效液相色谱-串联质谱(UPLC-MS/MS)检测生乳与豆制饮品中咪唑烟酸农药残留的方法。结果表明,该方法的前处理条件为采用甲酸∶乙腈=5∶995(V/V)提取,HLB固相萃取柱净化,20%乙腈水溶液定容。选择电喷雾离子源正离子(ESI+)多反应监测(MRM)模式,采用UPLC-MS/MS测定咪唑烟酸,外标法定量。在此条件下,咪唑烟酸在2.0~30.0μg/L质量浓度范围内线性关系良好,相关系数R2>0.99,生乳和豆制饮品中咪唑烟酸的检出限(LOD)和定量限(LOQ)均分别为0.002 mg/kg、0.005 mg/kg,加标回收率为80.77%~90.35%,精密度试验结果的相对标准偏差(RSD)为1.43%~5.27%,说明该方法简便、快速、准确,具有一定的推广价值,可用于生乳与豆制饮品中咪唑烟酸残留量检测。

The pretreatment conditions of imazapyr in raw milk and soybean drinks were studied,aiming to establish a method for the detection of imazapyr residues in raw milk and soybean drinks by ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The results showed that the pretreatment conditions of the method were as follows:extraction with formic acid:acetonitrile=5∶995(V/V),purification with HLB solid phase extraction column,constant volume with 20%acetonitrile water solution.Selecting electrospray ionization positive ion(ESI+)multiple reaction monitoring(MRM)mode,the imazapyr was determined by UPLC-MS/MS and quantified by external standard method.Under these conditions,the imazapyr had a good linear relationship in the concentration range of 2.0-30.0μg/L with correlation coefficient R2>0.99,the limit of detection(LOD)and the limit of quantitation(LOQ)of imazapyr in raw milk and soy drinks were both 0.002 mg/kg and 0.005 mg/kg,respectively,the standard recovery rate was 80.77%-90.35%,and the relative standard deviation(RSD)of precision test results was 1.43%-5.27%,indicating that the method was simple,rapid and accurate,with certain popularization value,and could be used for the determination of imazapyr residues in raw milk and soybean drinks.