Pharmaceuticals in grocery market fish fillets by gas chromatography–mass spectrometry

•A reproducible GC–SIM-MS method is used and validated for drugs analysis in fish.•Edible fish samples from the local grocery markets were evaluated.•Samples were homogenized, extracted, concentrated and examined.•DZP for the first time in edible fish fillets.•The concentrations were lower than the environmental fish. Occurrences of pharmaceuticals are evident in aquatic organisms. A reproducible gas chromatography–mass spectrometry (GC–MS) method using selected ion monitoring (SIM) has been used to determine the anti-histamine diphenhydramine (DPH), anti-anxiety diazepam (DZP), anti-seizure carbamazepine (CZP) drugs and their metabolites in grocery stores fish that were homogenized, extracted, pre-concentrated, cleaned up, and examined. Identifications of the compounds in extracts were obtained by comparing similar mass spectral features and retention properties with standards. Among nine frequently detected drugs, only DPH and DZP were observed and ranged from 0.61 to 6.21 and 1.99 to 16.57ng/g, respectively, in fourteen fish species. These concentration values were lower than the environmental fish. Mean spike recoveries of analytes exceeded 75% with relative standard deviations (RSD)