QuEChERS-based analysis and ecotoxicological risk of select antibiotics in dumpsite leachates, hospital wastewater and effluent receiving water in Ibadan, Nigeria.

There is currently a dearth of information on the determination, occurrence and ecotoxicological risk of antibiotics in dumpsite leachates and hospital wastewater in Africa. A quick, easy, cheap, effective, rugged and safe (QuEChERS) protocol which combines extraction and clean-up in one step was optimized for the determination of antibiotics sulfadoxine, sulfamethazine and trimethoprim in dumpsite leachates and hospital wastewater. The occurrence and ecotoxicological risk of target antibiotics were investigated in wastewater from two hospitals, effluent receiving water and leachates from three dumpsites in Ibadan, Nigeria. Recoveries in hospital wastewater ranged from 53 to 116% while recoveries ranged from 50 to 89% in leachates. Method limits of quantification ranged from 0.7 to 12.1 µg L in hospital wastewater and from 6.2 to 38.8 µg L in leachates. Intra-day precisions (% RSD) were ≤ 21%. High concentrations of target antibiotics were measured: up to 475 µg L for sulfamethazine in leachates, 118 µg L for trimethoprim in hospital wastewater and 117 µg L for sulfadoxine in effluent receiving water. Sulfadoxine presented high risk to algae, daphnid and fish in hospital wastewater, effluent receiving water and leachates. This work highlights the need for adequate and sound management of wastes containing pharmaceuticals in Nigeria.