DETERMINATION OF 26 ANTIBIOTICS IN GROUNDWATER BY DIFFUSIVE GRADIENTS IN THIN FILMS TECHNIQUE COMBINED WITH UPLC-MS/MS

Antibiotic contamination in groundwater has been concerned in recent years. Due to the trace-level concentration of antibiotics, the processes for sampling, extraction and detection are highly required. The diffusive gradients in thin films (DGT) is used to establish the in situ enrichment sampling method of antibiotics in groundwater, and antibiotics such as sulfonamides, quinolones, tetracyclines and macrolides are successfully enriched. Besides, the ultra-high performance liquid chromatogrphy tandem mass spectrometry (UPLC-MS/MS) is applied for the detection method of 26 typical antibiotics in groundwater, with optimized extraction conditions. The results show that the sampling and testing methods have good enrichment effect and detection sensitivity for analysis of antibiotics in groundwater. The appropriate in-situ enrichment sampling time of groundwater is 20-30 d, with instrument detection limit of 0.002-0.074 ng/L, average recovery of 47.7%-94.6% and precision of 4.45%-10.84%. The in situ enrichment sampling method of antibiotics in groundwater through DGT is simple and can be used for trace analysis of antibiotics in groundwater combined with UPLC-MS/MS.