The Development of SPE Procedures and an UHPLC Method for the Simultaneous Determination of Ten Drugs in Water Samples

Analytical procedures for the determination of pharmaceuticals from different therapeutic groups were proposed. These groups included the corticosteroids prednisolone and dexamethasone; the beta-blockers sotalol, metoprolol, propranolol, and carvedilol; and the analgesic nonsteroidal anti-inflammatory drugs paracetamol, aspirin, metamizole, and ketoprofen. Reversed-phase ultrahigh performance liquid chromatography with an ultraviolet detector, different columns, different mobile phases, and gradient elution programmes were used to obtain the best separations within the shortest possible time. Solid-phase extraction was examined as a preconcentration step. The Oasis HLB column, with the highest recoveries (over 90% for most of the drugs), was chosen for the analysis of surface waters. Limits of detection ranged from 0.06 to 0.39 mu g L(-1) for all drugs after optimisation of all analytical steps.