[Investigation of 14 selected antibiotics in sediments of the typical cross sections of Tiaoxi River].

The occurrence and distribution of 14 selected antibiotics in sediments of the typical cross sections of Tiaoxi River were analyzed by UPLC/MS/MS. The 14 antibiotics includes tetracycline (TC), oxytetracycline (OTC), chlortetracycline (CTC), doxycycline (DXC), sulfadiazine (SD), sulfamethoxazole (SMZ), sulfamethazine (SMX), norfloxacin (NFC), ofloxacin (OFC), enythromycin-H2O (ETM-H2O), roxithromycin (RTM), chloramphenicol (CPC), thiamphenical (TPC) and florfenicol (FFC). The results show that almost all sediment samples are unavoidably contaminated with antibiotics (detection frequency is more than 70%), and the dominant contaminants are TC, OTC, CTC and DXC, which range from 0.1 to 55.7, 0.7 to 276.6, 6.5 to 131.6 and 6.0 to 15.6 microg x kg(-1), respectively. The concentration of TC, OTC, CTC and DXC observed are as high as 1794.2, 9287.5, 1823.6, 1 149.5 microg x kg(-1) dry weight, in the sediments of the main stream around an outfall of a pig farm respectively. This implied that waste water discharge from animal husbandry was probably one of the main sources to the contamination of these antibiotics in the sediment of Tiaoxi River. Besides the four dominant antibiotics, sulfadiazineshould also be concerned due to its high concentration of 251.6 microg x kg(-1) in the sediment around the outfall of the pig farm.