高效液相色谱-串联质谱法测定动物肌肉组织中氯霉素、甲砜霉素和氟苯尼考残留量

High Performance Liquid Chromatography-Tandem Mass Spectrometric Determination of Chloramphenicol,Thiamphenicol and Florfenicol Residues in Animal Muscles

采用液相色谱-串联质谱(LC-MS/MS)法测定动物肌肉组织中氯霉素,甲砜霉素和氟苯尼考三种药物的残留量。添加氘代氯霉素(d5-氯霉素)作为内标,碱化乙酸乙酯提取,正己烷去除脂肪,省去固相萃取步骤直接上机定量。选择电喷雾离子源(ESI),负离子扫描多反应监测(MRM)模式,并优化了质谱参数,使仪器的灵敏度达到最高。氯霉素、甲砜霉素和氟苯尼考的检出限均达到0.01μg/kg。空白样品中添加氯霉素、甲砜霉素和氟苯尼考水平为0.02～1μg/kg时,三种药品的线性相关系数均大于0.9990。氯霉素平均回收率为92.8%～97.0%,甲砜霉素平均回收率为93.5%～96.6%,氟苯尼考平均回收率为91.2%～95.9%。

A high performance liquid chromatography-tandem mass spectrometric（HPLC-MS/MS） method was developed for the determination of chloramphenicol,thiamphenicol and florfenicol in animal muscles.Samples were spiked with deuterated chloramphenicol-d5（d5-CAP） as internal standard and extracted with alkaline ethyl acetate.The resulting extract was then treated with n-hexane for the removal of lipids and injected directly into the HPLC-MS/MS system without the requirement of solid-phase extraction clean-up.The electrospray ionization（ESI） mass spectrometry was run in negative ion multiple reaction monitoring mode.Instrumental parameters for MS analysis were optimized to maximize the detection sensitivity.The method exhibited the same limit of detection of up to 0.01μg/kg for the analytes.The internal standard method gave determination results closer to the actual values than the external method and the correlation coefficients of the linear regression equations developed for the determination of the analytes were all more than 0.9990.Mean recoveries of 5 replicates for chloramphenicol,thiamphenicol and florfenicol at the spike levels of 0.02-1μg/kg were within the ranges of 92.8%-97.0%,93.5%-96.6% and 91.2%-95.9%,respectively.