Occurrence of venlafaxine residues and its metabolites in marine mussels at trace levels: development of analytical method and a monitoring program

Coastal areas are subject to growing pressures and impacts because of the increase in human activities. Lipophilic organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs) or polychlorinated biphenyls (PCBs), have been monitored for decades within monitoring programs. However, until now, little information on the detection of so-called "emerging contaminants" such as hydrophilic organic compounds in the marine environment and no data on its metabolites or transformation products in marine organisms is available. In this report, a sensitive analytical methodology for identification and confirmation of venlafaxine (VEN) residues and five of its main metabolites in the marine mussels Mytilus galloprovincialis was validated. The sample preparation procedure was based on the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) approach. An analytical method was developed to quantify these compounds at trace levels by liquid chromatography coupled to high-resolution mass spectrometry. The method was then applied to marine mussels collected from the Mediterranean Sea in southeastern France. Residues of the antidepressant VEN were occasionally detected at ng/g dw level. In addition, the approach allowed us to identify several transformation products in the analyzed samples. N-desmethylvenlafaxine (NDV) was the most frequently de t e c t e d m e t a b o l i t e f o l l o w e d b y N, O - d i desmethylvenlafaxine (NODDV).