SPE-LC-MS/MS同时测定水中9种β-内酰胺类抗生素

Simultaneous Determination of Nine β-lactam Antibiotics by SPE-LC-MS/MS in Water

建立了以固相萃取-高效液相色谱串联质谱同时检测水体中9种β-内酰胺类抗生素(阿莫西林、头孢克洛、氨苄西林、头孢氨苄、头孢噻肟、头孢唑啉、青霉素G、头孢噻呋、青霉素Ⅴ)的检测方法。以Bond Elut Plexa PAX萃取小柱富集浓缩水样。对样品前处理过程中的上样p H、洗脱液进行了优化,以获得最高回收率。采用0.1%甲酸(V/V)-1 g/L甲酸铵水溶液和乙腈作为液相流动相,进行梯度洗脱。在HPLC-MS/MS多反应监测模式下进行定性定量分析。最终确定的实验条件为:上样p H为6,以4 m L 5%甲酸-甲醇(V/V)溶液进行分批洗脱。方法对9种抗生素的检出限为0.12~1.49 ng/L,加标回收率61.42%~108.08%,相对标准偏差为(n=3)2.39%~8.29%。并对大连近岸水体8个采样点水样进行了初步检测,每个采样点都有目标抗生素检出,总质量浓度在28.77~2 549 ng/L之间。除青霉素V类外各抗生素均有检出,青霉素G的检出次数与检出总质量浓度最高。结果表明,所建立的方法高效、灵敏、可靠,可用于水体中多种β-内酰胺类抗生素的分析。

A method for the determination of 9 β-lactam antibiotics in water including amoxicillin, cefaclor, ampicillin,cephalexin, cefotaxime, cefazolin, penicillin G, cefotaxime, and penicillin V was developed by using solid-phase extraction and high performance liquid chromatography-tandem mass spectrometry（SPE-HPLC-MS/MS）. Water samples were enriched by Bond Elut Plexa PAX cartridge. The sample p H and eluent of the sample preparation process were optimized to obtain the highest recoveries. Five antibiotics were separated by gradient elution with the mobile phases of 0.1%（V/V） formic acid and 1 g/L ammonium formate in water and acetonitrile. Qualitative and quantitative analysis were performed in multiple reaction monitoring（MRM） mode by HPLC-MS/MS. The final experimental conditions were the sample pH 6, and eluent 4 mL of 5% formic acid methanol（V/V）solution. The method detection limits（MDLs） were in the range of 0.12 ng/L-1.49 ng/L and the recoveries of 9 antibiotics in water ranged from 61.42%-108.08%, the relative standard deviations（n=3） were 2.39%-8.29%. The developed method was applied to the analysis of 8 water samples from Dalian. The results showed that the antibiotics could be detected in all water samples. The total mass concentration was in the range of 28.77 ng/L-2 549 ng/L. All the target antibiotics were detected except penicillin V. The detection rate and mass concentration of penicillin G were the highest. The results showed that the developed method is efficient, sensitive and reliable, which is suitable for the detection of antibiotics in water samples.