From surface water to aquatic macrophytes: Eichhornia crassipes as a complementary matrix for LC–HRMS screening of pharmaceuticals and psychoactive substances

The selection of an appropriate environmental matrix remains a critical factor in HRMS-based suspect screening of emerging contaminants. Although surface water is the most commonly investigated matrix, alternative biological matrices may provide complementary information on contaminant occurrence. In this study, Eichhornia crassipes (water hyacinth) and co-located surface-water samples from the Asi River (Orontes River) were comparatively evaluated as screening matrices for pharmaceuticals and psychoactive substances using an LC–HRMS workflow. Surface-water samples were extracted by solid-phase extraction (SPE), whereas plant tissues were processed using solvent extraction followed by liquid–liquid extraction (LLE) and SPE-based clean-up under different pH conditions to accommodate the complexity of the plant matrix. A suspect-screening approach was applied, and the Schymanski framework was used to assess compound annotation confidence. A total of 19 compounds were detected in E. crassipes, whereas 8 compounds were detected in the corresponding surface-water samples under the applied conditions. The detected substances included compounds confirmed with authentic reference standards (morphine, benzoylecgonine, hydromorphone, codeine, methamphetamine, methylphenidate, and cocaine), as well as probable or tentative annotations including ephedrine, ritalinic acid, venlafaxine metabolites, synthetic cathinones (N-propyl butylone and N-butyl pentylone), PB-22 metabolites, propyphenazone, propofol, and trifluoperazine. Several PB-22 metabolite- and synthetic-cathinone-related features were annotated in E. crassipes, and the plant matrix provided broader qualitative detection coverage in this single sampling event than co-located grab surface-water samples. These findings indicate that E. crassipes may provide complementary information for LC–HRMS-based environmental analysis of pharmaceuticals and psychoactive substances and highlight the importance of matrix selection and matrix-tailored sample preparation in suspect-screening workflows.