BACKGROUND Currently, the environmental detection of antibiotics is receiving extensive attention, but there is still a lack of methods that can simultaneously analyze seven categories of antibiotics in surface water and groundwater.

OBJECTIVES To establish a method that can detect thirty-seven antibiotics (15 sulfonamides, 2 tetracyclines, 3 macrolides, 8 quinolones, 2 chloramphenicols, 2 β-lactams and 5 other kinds) simultaneously.

METHODS Solid phase extraction coupled with ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS) was used to quantify the concentration of antibiotics.

RESULTS The method had good sensitivity and enrichment effect for the surface water and groundwater, the recoveries ranged from 60% to 130%, the detection limits ranged from 0.6 to 10.6ng/L. The method was applied to the determination of antibiotics in surface water of the Yongding and Chaobai Rivers, and groundwater of the Chaobai River in Beijing. Sulfonamides, quinolones and macrolides were the main antibiotics in the surface water of the Yongding River, and the detection rates were 88.9%, 55.6% and 33.3%, respectively. The highest concentration of floxacin was 111.9ng/L. Sulfonamides, quinolones and chloramphenicols were the main antibiotics in the surface water of the Chaobai River with detection rates of 100%. The highest concentration of tilmicosin was 71.6ng/L. Sulfonamides, quinolones and β-lactams antibiotics were the main antibiotics in the groundwater of the Chaobai River Basin, and the detection rates of were 66.7%, 55.6% and 22.2%, respectively. The highest concentration of sulfadiazine was 69.3ng/L. In both surface water and groundwater, the detection rate and concentration near the sewage treatment plant were significantly higher than those at other points.

CONCLUSIONS The method established in this study is simple, rapid and accurate, which can be used for the simultaneous determination of 37 antibiotics in seven categories in surface water and groundwater. It provides antibiotic analysis method support for surface water and groundwater investigation, and provides a scientific basis for rational utilization of water resources and management of new pollutants in water.