高效液相色谱-电喷雾串联质谱法检测环境水样中22种抗生素类药物

建立了高效液相色谱-电喷雾串联质谱(HPLC-ESI MS/MS)分析环境水样中22种抗生素类药物的方法。采用HLB固相萃取柱对环境水样中的目标化合物进行富集、净化,然后以6 mL氨水-甲醇(5:95, v/v)溶液洗脱。收集的洗脱液经氮气吹干至1 mL,然后进行HPLC-ESI MS/MS分离分析。色谱流动相A相为甲醇-乙腈(1:1, v/v), B相为0.3%(体积分数)甲酸水溶液(含0.1%(体积分数)甲酸铵,pH 2.9);色谱柱为XTerra MS C18柱。质谱检测采用正离子扫描,多反应监测模式。分别以自来水和污水作为基质,22种抗生素类药物的加标平均回收率分别为54.9%～130%和57.4%～138%,相对标准偏差(n=3)分别为2.85%～28.6%和2.02%～23.2%;方法的检出限为0.05～0.5 ng/L。将建立的方法应用于北京市高碑店湖和小清河水样的分析,结果表明在两个水样中均有部分抗生素类药物检出。

Determination of 22 antibiotics in environmental water samples using high performance liquid chromatography-electrospray ionization tandem mass spectrometry

A method for the determination of 22 antibiotics in environmental water samples was developed by using high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI MS/MS). The target antibiotics in water samples were enriched and cleaned-up by HLB solid-phase extraction (SPE) cartridges, and then eluted with 6 mL ammonium hydroxide-methanol (5:95, v/v). The eluate was collected and concentrated to 1 mL under a gentle stream of nitrogen gas, and then analyzed by HPLC-ESI MS/MS in positive electrospray ionization and multiple reaction monitoring (MRM) mode. The separation was carried out on an XTerra MS C18 column with mobile phases of A, methanol-acetonitrile (1:1, v/v), and B, 0.3% formic acid/water (containing 0.1% ammonium formate, v/v, pH 2.9). The results showed that the average recoveries of antibiotics in tap water and wastewater were 54.9%~130% and 57.4%~138%, respectively, and the corresponding relative standard deviations (RSD, n=3) were 2.85%~28.6% and 2.02%~23.2%, respectively. The method detection limits were 0.05~0.5 ng/L. The developed method was applied to analyze the water samples of Gaobeidian Lake and Xiaoqinghe River in Beijing. The results showed that some antibiotics were detected both in the two samples.