Occurrence of antibiotics in the surface water of urban river, Shenzhen, China

The occurrence, distribution of 21 antibiotics, including eleven fluoroquinolones (FQs), and seven sulfonamides (SAs), two macrolides (MLs) and chloramphenicol in the urban river in March (dry season) and July (wet season),... [ view full abstract ]

The occurrence, distribution of 21 antibiotics, including eleven fluoroquinolones (FQs), and seven sulfonamides (SAs), two macrolides (MLs) and chloramphenicol in the urban river in March (dry season) and July (wet season), 2013 were investigated. Samples were analysed using ultra high-performance liquid chromatography coupled to a mass spectrometer (UHPLC-MS/MS) after clean up and pre-concentration by solid phase extraction (SPE). The studies revealed the occurrence of 21 classes of antibiotics including sulfadiazine, sulfamethoxazole, sulfamethazine, sulfamerazine, sulfachinoxalin, sulfanilamide, sulfathiazole, sulfacetamide, sulfapyridine, sulfachlorpyridazine, sulfisoxazole, levofloxacin, enoxacin, enrofloxacin, nadifloxacin, ciprofloxacin, norfloxacin, lomefloxacin, erythromycin, roxithromycin and chloramphenicol. Their concentrations ranged from 3.9 to 2554.7 ng/L. The most frequently detected antibiotics were found to be sulfonamides and fluoroquinolones in surface water. The concentration of antibiotics from samples in March was higher than that in July. The highest total concentration of 21 antibiotics in water samples were 2554.7 and 1948 ng/L in March and July, respectively. In particle matters, low level of sulfonamides was detected during July and the highest total concentration of antibiotics in all samples was 116ng/L. In terms of the river reach, the contamination levels of antibiotics were much higher in main stream than that in branch. The data collected implies that while insufficiently treated wastewater contributes to surface water contamination, human activities also contribute appreciably to the antibiotics loading of the urban river. The results provided basic data for evaluating the health and ecological risk of antibiotics in these areas.