Determination of selected human pharmaceutical compounds in effluent and surface water samples by high-performance liquid chromatography-electrospray tandem mass spectrometry

A simple method is presented for the analysis of 13 pharmaceutical and pharmaceutical metabolite compounds in sewage effluents and surface waters. The pharmaceutical compounds were extracted using a generic solid-phase extraction (SPE) procedure using Phenomenex Strata X as a stationary phase. Extracts were quantitatively analysed by four separate reversed-phase high-performance liquid chromatography-electrospray tandem mass spectrometry (HPLC-ESI-MS/MS) techniques and quantified by comparison with an internal standard ([ C]-phenacetin). Recoveries and limits of detection (LOD) for sulfamethoxazole (120%, 50ngl), acetyl-sulfamethoxazole (56%, 50ngl), trimethoprim (123%, 10ngl), erythromycin (73%, 10ngl), paracetamol (75%, 50ngl), ibuprofen (117%, 20ngl), clofibric acid (83%, 50ngl), mefenamic acid (24%, 50ngl), diclofenac (62%, 20ngl), propranolol (45%, 10ngl), dextropropoxyphene (63%, 20ngl) and tamoxifen (42%, 10ngl) were all acceptable. The recovery of lofepramine (4%) was too low to be of use in a monitoring programme. Application of the method to samples collected from UK sewage effluents and surface waters showed detectable concentrations of mefenamic acid, diclofenac, propranolol, erythromycin, trimethoprim and acetyl-sulfamethoxazole in both matrices. Ibuprofen and dextropropoxyphene were detected in sewage effluents alone. All other pharmaceutical compounds were below the methods limits of detection