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-13]-phenacetin). Recoveries and limits of detection (LOD) for sulfamethoxazole (120%, 50 ng l(-1)), acetyl-sulfamethoxazole (56%, 50 ng l(-1)), trimethoprim (123%, 10 ng l(-1)), erythromycin (73%, 10 ng l(-1)), paracetamol (75%, 50 ng l(-1)), ibuprofen (117%, 20 ng l(-1)), clofibric acid (83%, 50 ng l(-1)), mefenamic acid (24%, 50 ng l(-1)), diclofenac (62%, 20 ng l(-1)), propranolol (45%, 10 ng l(-1)), dextropropoxyphene (63%, 20 ng l(-1)) and tamoxifen (42%, 10 ng l(-1)) 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. (C) 2003 Elsevier B.V. All rights reserved.