Development of an analytical methodology for the analysis of priority cytostatics in water

The consumption of cytostatics has remarkably increased over the last years due to the high cancer incidence worldwide. In previous studies, seven cytostatics were already recognized to potentially induce chronic effects in aquatic organisms, taking into account their estimated concentrations in surface waters: cyclophosphamide (CYC), capecitabine (CAP), mycophenolic acid (MPA), imatinib (IMA), bicalutamide (BICA), prednisone (PRED) and 5-fluorouracil (5FU). The objective of the present study was to simultaneously analyse these 7 prioritized compounds, which have the highest chances to be found in surface and wastewaters. The analytical challenge relies in the determination of these very polar compounds, which have different chemical and structural properties. Solid-phase extraction with an Ultra Performance Liquid Chromatograph-Mass Spectrometer in electrospray ionization mixed mode (5-fluorouracil and bicalutamide in negative mode and the others in positive one) was developed to determine seven cytostatics in wastewater and surface water. Among eight tested cartridges with different sorbents and conditions, the best extraction performance was attained with Oasis WAX at pH 10, with recoveries ranging from 31 ± 4 (5FU) and 103 ± 17% (MPA). Regarding the chromatographic analysis, the best results were achieved with an XBridge amide column. The final analytical methodology was successfully applied for the analysis of real water samples, confirming the presence of risky cytostatics in surface and wastewaters.