HPLC-MS/MS Method for Quantification of Pharmaceuticals in Subtropical Rivers and Water Treatment Plants in Brazil

Abstract

A multiclass analytical method for the investigation of 25 pharmaceuticals in the main rivers of the four largest hydrographic basins and an industrial water treatment plant in Curitiba, Brazil was developed and validated. The analysis of the pharmaceuticals was done using SPE-HPLC-MS/MS. The LoD and LoQ concentrations were 10–100 ng L–1 and 20–200 ng L–1, respectively. The extraction and quantitation of the 25 compounds proved to be precise and accurate. Surface water samples collected during the spring of 2019 (n=16) were analyzed. Caffeine, lidocaine, sulfamethoxazole, and carbamazepine were the main compounds present in the river samples. Sulfamethoxazole was the antibiotic found in the highest concentrations. Other antibiotics, psychiatric drugs, anti-inflammatories, analgesics, antiretrovirals, and antidiabetics were also frequently detected and quantified. It was also observed that the treatment employed at the treatment station did not efficiently remove all pharmaceutics investigated. The results of this study indicate an intense anthropogenic influence in the Iguaçu basin, mainly due to the presence of domestic sewage. The lack of sanitation has a negative impact on the water quality of the Iguaçu River, which is highly degraded due to the influence of the tributaries of the Metropolitan Region of Curitiba.