Bioconcentration and Biotransformation of Pharmaceuticals in Oryzias latipes using Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS)

Abstract

The occurrence of pharmaceuticals in the aquatic environment has been increasing steadily owing to the increasing use of pharmaceuticals in our daily life. This results in increasing challenges of environmental health risk as pharmaceuticals in the surface water can be accumulated and transformed in aquatic organisms. The purpose of this study was to predict the bioconcentration and biotransformation of several pharmaceuticals in Japanese medaka (Oryzias latipes) using a 96 h exposure test. Based on an investigation of the most frequently detected pharmaceuticals in the surface waters in South Korea, 11 target compounds were selected including atenolol, caffeine, carbamazepine, diclofenac, fluoxetine, irbesartan, losartan, mefenamic acid, metoprolol, naproxen, and venlafaxine. A bioconcentration factor of 1.9, 31.3, and 10.7 was expected in fish owing to the accumulation of carbamazepine, fluoxetine, and mefenamic acid, respectively. A total of 12 biotransformation products (BTPs) were tentatively identified via oxidation, hydroxylation, dealkylation, and demethylation reactions. In summary, it is expected that these BTPs represented by molecular structures derived from their parent compounds can be utilized to evaluate the change in toxicity of BTPs compared to that of the parent compounds. Key Words: Pharmaceuticals, Oryzias latipes, Bioconcentration, Biotransformation, LC-HRMS, Suspect screening, Non-target screening