超高效液相色谱-串联质谱法测定猪肉中5种硝基咪唑残留量

Determination of five nitroimidazoles in pork by ultra performance liquid chromatography-tandem mass spectrometry

建立了超高效液相色谱-串联质谱法(UPLC-MS/MS)测定猪肉中5种硝基咪唑残留量的方法。样品采用乙腈提取、QuEChERS净化,经C_(18)固相萃取柱净化、浓缩,再用超高效液相-串联质谱仪(UPLC-MS/MS)采用多反应检测(MRM)模式进行测定,外标法定量。结果表明:在设定条件下,5种硝基咪唑在1~500μg/L浓度范围内呈良好的线性关系(R^(2)>0.998),定量限为0.5~0.6μg/kg。在低、中、高3个添加水平下,5种硝基咪唑的平均回收率在79.6%~103.2%之间,相对标准偏差在2.1%~9.1%之间。该方法前处理简单快捷、灵敏度高、回收率和重现性良好,适用于猪肉中5种硝基咪唑残留量的测定。

A method for determination of five nitroimidazole residues in pork by ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)was developed.The samples were extracted with acetonitrile,and purified by QuEChERS method,and then cleaned-up and concentrated by solid-phase extraction(SPE)with C_(18) column.Five nitroimidazoles contents were measured by UPLC-MS/MS in the multiple reaction monitoring(MRM)mode by employing the external standard method.Under the experimental condition,five nitroimidazoles had good resolutions and well linearities(R^(2)>0.998)in detection ranges.The limits of quantification for five nitroimidazoles were 0.5~0.6μg/kg.The average recoveries from spiked blank samples ranged from 79.6%to 103.2%with relative standard deviation(RSD)between 2.1%and 9.1%.With the advantages of convenience,sensitivity,good recoveries and repeatability,the method was suitable for the detection of five nitroimidazoles in pork.