Determination of 14 Antibiotics in Environmental Water Samples Using Solid Phase Extraction-High Performance Liquid Chromatography-Tandem Mass Spectrometry (SPE-HPLC-MS/MS)

Objectives An analytical method of solid phase extraction-high performance liquid chromatography-tandem mass spectrometry (SPE-HPLC-MS/MS) was developed for the determination of 14 antibiotics (5 categories) including macrolides, fluoroquinolones, lincosamides, β-lactam and tetracyclines in environmental water samples.

Methods Treated water samples were concentrated by solid phase extraction (SPE) through hydrophilic lipophilic balance (HLB) cartridge, eluted by methanol, dried by nitrogen gas and re-dissolved, and analyzed by HPLC-MS/MS. A CAPCELL PAK C₁₈ column was adopted as the analysis column with mobile phases of gradient elution of acetonitrile-0.1% formic acid, the positive ion mode was adopted for electrospray to ionize and the mass spectrometry signal was scanned in multiple reactions monitoring (MRM) mode, the antibiotics were quantified by external standard method.

Results The concentrations of 14 antibiotics were in the range of (2.0~1 000) μg/L, showing a good linear relationship with limits of detection of (0.1~0.2) ng/L. The average recoveries of 14 antibiotics from negative water samples and river water samples as substances were in the range of 68.3%~96.1% and 64.2%~113.3%, respectively, and the relative standard deviations (n=6) of 1.7%~11.4% and 1.5%~9.5%, respectively. The developed method was applied in detection and analysis of Dongjiang River in Dongguan. The result showed that six antibiotics were determined with the concentration in the range of 2.49~46.7 ng/L.

Conclusions With high sensitivity and good accuracy, the method could be employed in the determination of multiple antibiotics in environmental water samples.