全自动固相萃取-超高效液相色谱串联质谱法测定地表水中18种头孢菌素

Determination of 18 Cephalosporin Antibiotic Residues in Surface Water by Automatic Solid Phase Extraction Ultra Performance Liquid Chromatography Tandem Mass Spectrometry

建立了超高效液相色谱串联质谱(UPLC-MS/MS)法测定地表水中18种头孢菌素的方法。采用全自动固相萃取技术进行前处理,地表水样经HLB固相萃取小柱富集后,用1.0%(V/V)的甲酸溶液(溶剂为甲醇)洗脱。优选BEHShield RP18(1.7μm,2.1mm×100mm)色谱柱进行分离,在电喷雾正离子(ESI+)模式下电离,多反应模式(MRM)下检测,外标法定量。结果表明:18种头孢菌素在5.0~100μg/L范围内线性关系良好,相关系数(r)均>0.999,方法检出限为0.5~1.8ng/L,测定下限为2.0~7.2ng/L。对地表水样品进行加标回收实验,18种头孢菌素的相对标准偏差(RSD)为0.5%~14.5%,加标回收率为64.3%~92.8%。该方法自动化程度高,结果稳定可靠,适用于地表水中头孢菌素的测定。

In this study,an analytical method of ultra performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS)was established,which can simultaneously determine the residues of 18 cephalosporins in surface water.The automatic solid phase extraction technology is used for pretreatment.Surface water samples are enriched by HLB solid phase extraction column and eluted with 1.0%(V/V)formic acid methanol solution.BEH Shield RP18(1.7μm,2.1mm×100mm)chromatographic column is preferred to be used for separation.It can be ionized in the positive mode of electrospray(ESI+),be detected in multiple reaction mode(MRM)and measured by external standard method.The results showed that the linear relationship of 18 cephalosporin antibiotics is good in the concentration range of 5.0~100μg/L,the correlation coefficients(r)are greater than 0.999,the detection limit of the method is in the range of 0.5~1.8 ng/L,and the quantitative limit is in the range of 2.0~7.2 ng/L.Standard addition recovery experiments on surface water samples showed that the recoveries of cephalosporins are 64.3%~92.8%with the relative standard deviations in the range of 0.5%~14.5%.With high level of automation and stable and reliable results,the current method is suitable for the determination of cephalosporins in surface water.