Screening and quantification of pharmaceuticals and their metabolites in municipal wastewater treatment facilities in Guangzhou, China

The combination of qualitative methods with quantitative analysis of pharmaceuticals and their metabolites in wastewater treatment plants using liquid chromatography coupled with quadrupole time-of-flight high-resolution mass spectrometry is presented. The selected pharmaceuticals were found at a low or medium level in raw wastewater, compared with previous studies around the world. The removal efficiencies of sulfamethoxazole in the four parallel biological treatment processes were similar. Data-independent and data-dependent mass spectrometry acquisition methods (All Ions MS/MS and auto MS/MS) were employed for qualitative analysis. Five of the 18 tentatively identified compounds resulted from data-independent acquisition mode were confirmed with standards. Thirty-nine pharmaceuticals and seven metabolites were tentatively identified using data-dependent acquisition mode. The parent pharmaceuticals and their metabolites, such as caffeine and its three metabolites (3-methylxanthine, 1,7-dimethyluric acid, and paraxanthine), were detected in wastewater. Irbesartan and valsartan were tentatively identified in both positive and negative modes. The present study demonstrates that both data-dependent and data- independent acquisitions are suitable and reliable for tentative determination of pharmaceuticals and their metabolites in municipal wastewater.