液相色谱-串联质谱结合谱库检索测定猪组织中的9种β-兴奋剂残留量

建立了猪组织中9种β-兴奋剂(克伦特罗、莱克多巴胺、沙丁胺醇、利托君、特布他林、班布特罗、妥布特罗、西马特罗和异舒普林)多残留的液相色谱-四极杆/线性离子阱串联质谱(QTrap LC-MS/MS)检测方法。样品经β-葡萄糖醛苷酶/芳基硫酸酯酶酶解提取,液液萃取净化,以乙腈-甲酸水溶液为流动相,经C18柱分离后用QTrap LC-MS/MS进行多反应监测(MRM)、信息相关采集(IDA)、增强子离子扫描(EPI)和谱库检索分析。9种β-兴奋剂的线性范围为0.1～50.0 μg/L,线性关系良好(r＞0.99);样品中9种目标物在0.5、1.0和5.0 μg/kg添加水平下的回收率为72.0%～95.1%,相对标准偏差为3.1%～12.1%;方法检出限为0.1～0.2 μg/kg。实际样品检测结果表明,本方法可实现猪组织样本中β-兴奋剂残留量的灵敏、准确的定性和定量分析。

Determination of nine β-agonist residues in pig tissues by liquid chromatography-tandem mass spectrometry combining with library search

A new method has been developed using a hybrid triple-quadrupole linear ion trap (QTrap) mass spectrometer for the fast detection and identification of nine β-agonists, clenbuterol, salbutamol, ractopamine, ritodrine, terbutaline, isoxsuprine, tulobuterol, cimaterol and bambuterol, in one single liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The homogenized tissue samples were purified with liquid-liquid extraction after enzymatic hydrolysis by β-glucuronidase/aryl sulfatase. After gradient elution separation on C18 LC column using acetonitrile and formic acid aqueous solution as the mobile phases, a multiple reaction monitoring (MRM) scan as survey scan and an enhanced product ion (EPI) scan as dependent scan were performed in an information dependent acquisition (IDA) experiment. Finally, the identification of the drugs was carried out by library search with a newly developed MS/MS library based on EPI spectra at three different collision energies in positive mode. The analytical method in the present study was well validated and good results were obtained with respect to precision, repeatability and spiked recovery. The limits of detection of residues were 0.1-0.2 μg/kg for β-agonists, and with a linear range from 0.1 to 50.0 μg/L. Three concentration levels of 0.5, 1.0 and 5.0 μg/kg were spiked in pig tissues, and the overall recoveries were between 72.0% and 95.1% with the relative standard deviations (RSDs) between 3.1% and 12.1%. The real sample test showed that this method could be used for sensitive and accurate determination of β-agonist residues in pig tissues.