Determination and Distribution Characteristics of 20 Antibiotics in Major Rivers and Bays of Shenzhen

Objectives To investigate the pollution situation of 20 common antibiotics from ten rivers and Shenzhen Bay in Shenzhen, and analyze their distribution characteristics.

Methods An analytical method was developed and adopted to determine 77 samples using ultra-high performance liquid chromatography/tandem mass spectrometry(UPLC-MS/MS).

Results 14 antibiotics were delermined in samples. The detection concentrations of sulfamethoxazole(SMX), oxytetracycline(OXY), and nitrofarazone(NFZ) were the highest. The determination frequencies of sulfamethoxazole(SMX), chloramphenicol, sulfameter were the highest. The Buji River, Shenzhen River, Guanlan River were severely polluted by antibiotics and showed a seasonal variation feature of higher antibiotics concentration in winter (dry season) and lower concentrations in summer (wet season). 75% of rivers were jointly polluted by three or moreantibiotics, in which, sulfonamide, tetracycline and chloramphenicol were predominant.

Conclusions In Shenzhen, 14 antibiotics pollution residuals existed in water bodies, and the overall pollution is in a relatively lower level.