[Pollution Characteristics and Risk Assessment of Antibiotics in Beiyun River Basin in Beijing]

To investigate the pollution characteristics and risk levels of antibiotics in water of the Beiyun River Basin in Beijing, the concentration of antibiotics was analyzed by using the solid-phase extraction and high-performance liquid chromatography-tandem mass spectrometry (SPE-HPLC-MS/MS) method. The results showed that seven types of four categories of antibiotics were detected in the samples from 12 sampling points; the total concentration of antibiotics including sulfapyridine, clarithromycin, azithromycin, roxithromycin, erythromycin, ofloxacin, and lincomycin ranged from 59.19 to 703.44 ng·L^-1. Among these antibiotics, the detection rate of clarithromycin, azithromycin, roxithromycin, ofloxacin, and lincomycin was 100%; that of erythromycin was 41.67%; and that of sulfapyridine was 33.33%. Compared with that in some rivers in China, the Azithromycin, Erythromycin, and Clarithromycin in the Beiyun River Basin were at a relatively high level. The ecological risk assessment results showed that the most sensitive species was algae. The health risk quotients indicated that sulfapyridine, lincomycin, roxithromycin, azithromycin, and erythromycin presented no risk for every age group, whereas the health risk of clarithromycin was at a low level.