固相萃取-高效液相色谱-串联质谱法测定牛乳和猪肉中5 种青霉素类抗生素

建立一种用固相萃取-高效液相色谱-串联质谱法检测牛乳和猪肉中苄星青霉素G、氨苄西林、苯唑西林、氯唑西林、双氯西林5 种青霉素类抗生素方法。样品经乙腈提取，Bond Elut C18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。结果表明，本方法5 种青霉素在2.0～200 μg/L范围内呈良好线性关系，线性相关系数大于0.999；牛乳样品添加回收实验，回收率为85.2%～122.7%，相对标准偏差为3.43%～16.8%（n=6）；猪肉样品添加回收实验在50 μg/kg和100 μg/kg添加水平，除氨苄西林外，回收率在94.3%～116.4%，相对标准偏差为1.62%～5.09%（n=6）。方法定量限为1.0～2.0 μg/kg。该方法具有简便快捷、准确度高、定量限低的优点，适用于牛乳和猪肉中青霉素类抗生素的测定。

Determination of 5 Penicillin Residues in Milk and Pork by SPE-HPLC-MS-MS

A method was established for the determination of 5 penicillin residues in milk and pork by solid-phase extraction
and high performance liquid chromatography-tandem mass spectrometry (SPE-HPLC-MS-MS). The samples were extracted
with acetonitrile, purified on a Bond Elut C18 column by solid-phase extraction, and finally detected by HPLC-MS-MS and
quantified by an external standard method. As a result, the method showed a good linearity with a correlation coefficient
higher than 0.999 in the range from 2.0 to 200 μg/L for 5 penicillin compounds. The average recoveries of these five
penicillins in milk were in the range of 85.2% to 122.7% with relative standard deviations (RSDs) of 3.43% to 16.8% (n =
6). As for pork samples spiked at 50 and 100 μg/kg, the average recoveries were between 94.3% and 116.4% except for ampicillin
with RSDs of 1.62% to 5.09%. The limit of quantification (LOQ) was in the range of 1.0–2.0 μg/kg. In conclusion, the method is
convenient, rapid, accurate and sensitive so that it can be applied to determinate penicillin residues in milk and pork.