液相色谱-串联质谱法测定育肥猪配合饲料中的阿奇霉素

Determination of Azithromycin in Formula Feed for Fattening Pigs by High Performance Liquid Chromatography-Tandem Mass Spectrometry

通过对提取溶剂、净化方法及色谱-质谱条件的优化,建立了配合饲料中阿奇霉素(AZM)的液相色谱-串联质谱测定方法。样品经乙腈超声波提取,MCX固相萃取柱净化,BDS Hypersil C_(18)(2.4μm,100 mm×2.1 mm)色谱柱分离,以甲醇-0.05 mol/L乙酸铵水溶液为流动相梯度洗脱,正离子模式电离,多反应监测模式检测,同位素内标法定量。在优化条件下,AZM在1~250μg/L范围内线性关系良好,相关系数(r^2)为0.999 1,检出限(S/N≥3)为2.8μg/kg,定量下限(S/N≥10)为8.4μg/kg;在0.5,1,5,10 mg/kg加标水平下,回收率为87.0%~106.6%,批内相对标准偏差为0.58%~5.4%,批间相对标准偏差为3.1%~5.4%。该方法准确、灵敏,选择性强,基质干扰小,可用于配合饲料中AZM的测定。

A method was developed for the determination of azithromycin in formula feed for fattening pigs by liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）.The sample was extracted with acetonitrile under ultrasonic assistance.Oasis MCX solid phase extraction column was used for purification,and the chromatographic separation was performed on a Hypersil BDS C18 column（2.4 μm,100 mm×2.1 mm） with gradient elution using 0.05 mol/L ammonium acetate-methanol（1∶9） as mobile phase.The detection of azithromycin was performed with positive ion under multiple reaction monitoring（MRM） mode.The internal standard isotope dilution method was used for quantification.A good linearity（r2=0.999 1） was obtained for azithromycin in the range of 1-250 μg/L.The limit of detection（LOD,S/N≥3） and the limit of quantitation（LOQ,S/N≥10） of azithromycin in the formula feed were 2.8 μg/kg and 8.4 μg/kg,respectively.Average recoveries ranged from 87.0% to 106.6% for the formula feed at spike levels of 0.5,1,5,10 mg/kg.The intra-RSDs for azithromycin were 0.58%-5.4% and the inter-RSDs were 3.1%-5.4%.The method is accurate and sensitive,and the matrix interference is small.The method could be applied in the determination of azithromycin in formula feed.