Screening and confirmation of steroids and nitroimidazoles in urine, blood, and food matrices: Sample preparation methods and liquid chromatography tandem mass spectrometric separations.

•New LC–MS/MS methods are developed for veterinary drugs.•Screening methods utilise supported liquid extraction.•Confirmatory methods employ solid phase extraction.•The applicability of methods is proven with incurred sample analysis.•Naturally contamination of prednisolone is detected in urine.