高效液相色谱-串联质谱法测定牛奶和奶粉中9种青霉素类药物残留量

Determination of Nine Penicillin Residues in Milk and Milk Powder by HPLC-MS/MS

建立一种检测牛奶和奶粉中9种青霉素类药物残留量的高效液相色谱-串联质谱方法。样品经乙腈-水提取,经HLB固相萃取柱净化,用高效液相色谱串联质谱检测,外标法定量。本方法的检出限,牛奶中氨苄西林、奈夫西林为1μg/kg,阿莫西林、哌拉西林、青霉素G、青霉素V、氯唑西林为2μg/kg,苯唑西林、双氯西林为4μg/kg;奶粉中氨苄西林、奈夫西林为8μg/kg,阿莫西林、哌拉西林、青霉素G、青霉素V、氯唑西林为16μg/kg,苯唑西林、双氯西林为32μg/kg。9种青霉素在1.0～50ng/mL范围呈良好线性,线性相关系数大于0.9888。牛奶的平均回收率为77.58%～97.77%,测定结果的相对标准偏差为4.24%～16.59%(n=10);奶粉的平均回收率在85.95%～96.78%之间,相对标准偏差为2.71%～13.41%(n=10)。该方法具有简便、快速、准确度高、检出限低的优点,适用于牛奶和奶粉中青霉素类抗生素的测定。

A method to determine 9 penicillin residues in milk and milk powder by high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS） was established.Samples were extracted by acetonitrile-water,cleaned by solid-phase extraction,detected by HPLC-MS/MS and quantified by external standard method.The detection limit was 1 μg/kg for ampicillin and nafcillin,2 μg/kg for amoxicillin,piperacillin,penicillin G,penicillin V and cloxacillin,4 μg/kg for oxacillin and dicloxacillin in milk,and was 8μg/kg for ampicillin and nafcillin,16 μg/kg for amoxicillin,piperacillin,penicillin G,penicillin V and cloxacillin,32 μg/kg for oxacillin and dicloxacillin in milk powder,respectively.The linearity was satisfactory with a correlation coefficient 0.9997 at concentrations ranging from 1.0 to 50 ng/mL.Spike average recoveries for the 9 penicillins in milk was in the range of 77.58% to 97.77% with a RSD of 4.24% to 16.59%（n = 10）,and Spike average recoveries in milk power in the range of 85.95% to 96.78% with a RSD of 2.71% to 13.98%（n = 10）.In conclusion,the established method is convenient,rapid,accurate and sensitive so that it may be applied to determinate penicillin residues in milk and milk powder.