Determination And Source Apportionment Of Three Classes Of Antibiotics In Beijing Wenyu Rivers

Antibiotic is widespread used throughout the world as medicine and animal growthpromoting agent. In recent years, the antibiotics are frequently detected from sewage,surface water, groundwater, drinking water, sludge, which will promote microbial drugresistance and antibiotic resistance genes, as a result, affect the ecosystem, put a threatto human health. It is important to analyse the antibiotic residues in aquatic environment,evaluate their risk and prevent the dissemination of resistant microorganisms. In view ofthe background, this research studied the distribution characteristics and sourceapportionment about macrolides, quinolones, tetracycline antibiotics in all49kinds ofsubstances pollution based on high performance liquid chromatography tandem massspectrometry method in Beijing Wenyu river.We sampled45river samples,13discharging sites, and4composite effluentsamples. For analyzing target antibiotics in water samples, the extraction by HLB SPEcartridge was combined with cleanup procedures using MAX cartridges. Matrix effectswere greatly reduced （<35%）, and the absolute recoveries of all chemicals ranged from55%to109%, MDLs were between0.1^-15.6ng L^-1in different water matrix, showing ahigh sensitivity.The total concentrations of tetracyclines are up to296.6ng L^-1in the45riversamples. TC, OTC, ICTC are detected with a frequency of90^-100%. The concentrationsof tetracycline are slightly below foreign. The total concentration of macrolide isbetween18are369.6ng L^-1, where CLA, ERY, ROX have a detection frequency of100%, TIL and KIT have a detection frequency of less than5%; quinoloneconcentrations:56.5^-1430.3ng L^-1; the detection frequency of OFL, GATI, FLUM is100%;DIF, MOXI, DANO, PEFL detection rate is less than10%. More attention shouldbe given to the fourth generation quinolone antibacterial GATI and MOXI, which havebeen banned for obvious side effects from North America clinical, however which havedetected in Beijing urban rivers,the median concentration of GATI is16.5ng L^-1.The concentrations of three classes antibiotic in13discharging sites are greaterthan which are river samples, the concentration of OTC was up to704.9ng L^-1in thedischarging sites; macrolide and quinolone concentrations were high up to645ng L^-1 and6589ng L^-1, respectively. Direct discharges and the effluents of STP are close tofarms and settlements. A principal component analyses withmultiple linear regressionbased on the profiles of all target compounds was applied to identify the sourceapportionment and to predict the contribution from different sources. It was found that75.5%of the mean macrolide antibiotics were contributed by freshly dischargeduntreated sewage and the effluents of STP,24.5%by an unknown source.40%of themean quinolone antibiotics were contributed by freshly discharged untreated sewageand33%by the effluents of STP,23.08%of the mean tetracycline antibiotics werecontributed by freshly discharged untreated sewage and the effluents of STP,62.66%bythe effluents of STP, and there be an unknown source, possibly pharmaceuticalmanufacturing plants or fishing ground.The drug-resistant bacteria quantity of TCs, FQs and those concentrations are inthe presence of logarithmic relation, which indicate the usage of antibiotics is the maincause of drug-resistant bacteria in Wenyuhe watershed.