固相萃取法结合液相色谱-串联质谱技术测定饲料中庆大霉素含量

Determination of Gentamicin in Feeds by Solid Phase Extraction Combined with Liquid Chromatography-Tandem Mass Spectrometry

本研究建立了一种固相萃取法结合液相色谱-串联质谱技术测定饲料中庆大霉素含量的方法。采用5%三氯乙酸提取液提取饲料样品,用PCX固相萃取柱净化,使用液相色谱-串联质谱检测,以2 mmol/L甲酸铵-0.1%甲酸溶液(A)-乙腈(B)为流动相,梯度洗脱,Agilent SB-Aq色谱柱分离。庆大霉素含量在1.0~100.0 mg/L线性关系良好(R 2>0.995);方法的检出限为0.03 mg/kg,定量限为0.1 mg/kg;庆大霉素在3个添加水平(1.0、10.0、100.0 mg/kg)下的平均回收率为81.5%~123.6%,相对标准偏差<15%。该方法易于使用,预处理简单,适用于测定饲料中的庆大霉素含量。

The aim of this experiment was to establish a method for the determination of gentamicin in feeds by solid phase extraction combined with liquid chromatography-tandem mass spectrometry(LC-MS/MS).The feed samples were extracted with 5% trichloroacetic acid extract,cleaned-up by a mixed cationic solid-phase extraction column(PCX),and determined by liquid chromatography-tandem mass spectrometry(LC-MS/MS),with 2 mmol/L ammonium formate-0.1% formic acid solution(A)-acetonitrile(B)as the mobile phase with gradient elution,and separated on an Agilent SB-Aq column.The linearity of gentamicin content was good in the range of 1.0~100.0 mg/L(R 2>0.995);the limit of detection of the method was 0.03 mg/kg,and the limit of quantification was 0.1 mg/kg;the average recoveries of gentamicin at three spiked levels(1.0,10.0 and 100.0 mg/kg)were 81.5% to 123.6%,and the relative standard deviations<15%.The method is simple in pretreatment,convenient in operation and suitable for the determination of gentamicin in feeds.