固相萃取/液相色谱-串联质谱法测定兽药制剂中非法添加8种硝基咪唑类药物

Determination of illegal addition of 8 nitroimidazoles in veterinary drug preparations by liquid chromatography-tandem mass spectrometry with solid-phase extraction

试验建立了固相萃取/液相色谱-串联质谱法测定兽药制剂中8种硝基咪唑类药物的方法。样品采用乙腈提取,SCX固相萃取柱净化,经Waters BEH C18(100 mm×2.1 mm,1.7μm)色谱柱分离,以0.1%甲酸水和乙腈为流动相进行梯度洗脱,质谱采用正离子模式扫描,MRM模式进行分析。8种硝基咪唑类化合物在10~500μg/L范围内线性关系较好,相关系数大于0.9999。方法检出限为0.02 mg/kg,定量限为0.05 mg/kg。待测物在0.05、0.10、0.50 mg/kg 3个浓度水平下平均回收率在84.1%~101.6%之间,相对标准偏差在2.74%~11.60%之间。该方法可用于兽药制剂中硝基咪唑类药物的测定。

A method was developed for the detection of eight nitroimidazoles in veterinary drug preparations by solid phase extraction purification with liquid chromatography tandem mass spectrometry(LC-MS/MS).The samples were extracted with acetonitrile,SCX solid phase extraction column was purified,separated by Waters BEH C18(100 mm×2.1 mm,1.7μm)chromatographic column,and gradient elution was carried out with 0.1% formic acid water and acetonitrile as mobile phases.The mass spectrometer was operated using positive under multiple reaction monitoring(MRM)mode.The results showed that there was good linear relationship(10~500μg/L)for the eight nitroimidazoles with the correlation coefficient more than 0.9999.The limit of detection(LOD)and limit of quantization(LOQ)were0.02 mg/kg and 0.05 mg/kg for the eight nitroimidazoles.The average recoveries was in the range of 84.1%~101.6%,the relative standard deviation was between 2.74% and 11.60% with the concentration levels at 0.05,0.10,and 0.50 mg/kg for the analytes.The proposed method can be applied to determination of nitroimidazoles in veterinary drug preparations.