Determination of pharmaceutical compounds in water samples by solid phase extraction and liquid chromatography with photodiode array detector

Abstract

In the present work, an analytical method for the simultaneous determination of four pharmaceutical compounds (carbamazepine, ketoprofen, naproxen and diclofenac), in water samples, was developed. The method involves sample treatment by solid phase extraction (SPE) using Oasis HLB cartridges and subsequent determination by high-performance liquid chromatography (HPLC) with photodiode array detector (PDA). SPE was optimized basis on three different elution solvents. Method was validated at three concentration levels (0,2 ng/mL, 2 ng/mL and 10 ng/mL) obtaining adequate results only for carbamazepine and naproxen. LC-PDA methodology developed was applied to the analysis of surface water coming from Millars River (Almassora, Castelló, Spain) and four treatment plants sited in Castelló province. None of pharmaceutical studied could be detected by LC-PDA. An alternative and sensitive method carried out by HPLC coupled to tandem mass spectrometry (MS/MS) confirmed the presence of several pharmaceuticals at low concentrations levels (below 1 ng/mL).