Determination of nonsteroidal anti-inflammatory drugs, caffeine, and triclosan in wastewater by gas chromatography-mass spectrometry

Pharmaceuticals are a class of chemicals whose fate in the environment has received increasing attention in the past few years. A quantitative method was developed for the determination of acidic pharmaceuticals (ibuprofen, naproxen, ketoprofen, mefenamic acid, and diclofenac), caffeine and the antibacterial triclosan in wastewater effluent. The compounds were extracted from wastewater samples on Waters Oasis HLB solid-phase extraction columns, derivatized with N,O-bis[Trimethylsilyl] trifluoroacetamide (BSTFA) and analyzed using gas chromatography-mass spectrometry. Estimated method detection limits ranged from 6 to 45 ng/L based on replicate analyses (n = 10). This method was applied to the analysis of effluent from a wastewater treatment plant and compounds were detected at concentrations of 18-72 ng/L.