上海青中9种抗生素的超高效液相色谱-串联质谱测定

为测定上海青中9种抗生素（氯霉素类、喹诺酮类），建立超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry，UPLC-MS/MS)的检测方法。将采集的样品经乙腈浸没超声提取，加入无水Na2SO4，NaCl盐析除去水分，使用C18及PSA吸附剂净化杂质，质量分数为0.1%的甲酸 乙腈溶液定容；然后在正负离子模式下，流动相分别为质量分数0.1%甲酸水-乙腈（ESI+）和超纯水-乙腈（ESI-），按设定梯度洗脱，并多反应监测测定9种抗生素。结果表明，氯霉素类抗生素在 0.5～10 μg/L 范围内线性关系良好，喹诺酮类抗生素在 5～100 μg/L 范围内线性关系良好，相关系数r均大于0.99，检出限为0.02～2.49 μg/kg，定量限为0.06～9.95 μg/kg。9种抗生素在10，50和100 μg/kg 3个添加水平下的回收率为76.6%～123.7%，相对标准偏差（n=7）为0.3%～11.0%。可见，该方法灵敏度高、净化效果好，适用于多种抗生素在上海青中的同时测定。

Determination of Nine Kinds of Antibiotics in Brassica chinensis L. by UPLC-MS/MS

To establish a method for the determination of nine antibiotics (chloramphenicol and quinolones) in Brassica chinensis L. by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).The collected samples were immersed in acetonitrile for ultrasonic extraction,then the salting-out agents anhydrous Na2SO4 and NaCl were added to remove water.C18 and PSA adsorbents were used to purify impurities,and 0.1% formic acid-acetonitrile solution was used to make up the volume.In the positive and negative ion mode,the mobile phases were 0.1% formic acid water acetonitrile (ESI+) and ultrapure water-acetonitrile (ESI-),respectively,and eluted according to the set gradient.Finally nine antibiotics were determined by multiple reaction monitoring.The results showed that the linear relationship of chloramphenicol antibiotics was good in the range of 0.5-10 μg/L,and the linear relationship of quinolone antibiotics was good in the range of 5-100 μg/L.The correlation coefficient r was greater than 0.99.The limit of detection was 0.02-2.49 μg/kg,and the limit of quantification was 0.06-9.95 μg/kg.The recoveries of the nine antibiotics at three levels of 10,50 and 100 μg/kg were 76.6%-123.7%,and the relative standard deviations (n=7) were 0.3%-11.0%.This method has high sensitivity and good purification effect,which is suitable for detecting multiple antibiotics in Brassica chinensis L.