Determination of antibiotics by SPE-LC-MS/MS in wastewater and risk assessment

In this study, conditions of solid phase extraction (SPE) for determination of some antibiotics such as trimethoprim, oxytetracycline, erythromycin, clarithromycin, azythromycin, doxycycline, sulfamethazine, ciprofloxacin, chlortetracycline, sulfamethoxazole in wastewaters were optimized. After the optimum volume and pH of the sample were determined, the effect of the concentration of the compounds and matrix were investigated. The highest recovery rates for antibiotic compounds were determined between 82% and 105% in 200 mL sample volume and pH 2.5. Then, antibiotic compounds were investigated in influent and effluent samples taken from Konya Urban Wastewater Treatment Plant. The concentration of the antibiotics was detected range of 0.11-101 ng/L in influent waters and less than dl-288 ng/L in effluent samples in wastewater treatment plant. Hazard quotients (HQs) of antibiotic compounds determined in WWTP effluents to evaluate the risk towards different aquatic organisms (algae, Daphnia magna and fish) were determined. Azythromycin for fish and erythromycin, sulfamethoxazole, ciprofloxacin, clarithromycin for algae posed a moderate risk while azythromycin, ciprofloxacin, clarithromycin, oxytetracycline posed a high risk for algae in the receiving environment.