Résumé
Environmental field studies have shown that carbamazepine (Cbz) is one of the most frequently detected human drugs in the different aquatic compartments. It has been regarded as a potential tracer in surface water due to its persistency to biodegradation and poor elimination during wastewater treatment, which makes to Cbz a pharmaceutical of high environmental relevance [1]. However, little information on the detection of such substance in marine organisms and no data about its metabolites or degradation products, is available in literature. In this way, the main objective of this study was to optimize and validate a simple and sensitive analytical methodology for the detection and quantitation of two anticonvulsants (carbamazepine and oxcarbazepine) and their main metabolites in marine mussel (Mytilus galloprovincialis). Most of the methods commonlyemployed until now, for analysis of pharmaceuticals from aquatic organisms are based on isolation of lipid, which often involve complicated extraction and clean up steps. These techniques are long and tedious, time-consuming and require large volumes of organic solvents. However, QuEChERS methodology presents a large number of advantages since it constitutes a fast and inexpensive procedure, simplifies and minimizes the time taken to extraction and clean-up processes. In view of this, a modified QuEChERS extraction method followed by analysis with liquid chromatography coupled with high resolution and high mass accuracy mass spectrometry was the procedure developed. The more demanding requirements regarding mass spectrometric confirmation currently set by EU regulations (Commission Decision 2002/657/EC) were taken into account [2]. Analyses were performed in MS and MS/MS which allowed revealing the different fragmentation pathways highly useful for the identification and quantitation of the isomeric compounds. Quantification limits were below 1 ng/g. Mean recovery ranged from 66-122%. Relative standard deviation was lower than 25% for intra and inter-day analysis. Finally, the method was applied to marine mussel samples collected from Mediterranean Sea in the southeast of France. Residues of the psychiatric drug carbamazepine were frequently found at levels up to 0.32 ng/g dried weight.Therefore, these organisms have proven to be a useful tool for monitoring micro-pollutants in marine water, facilitating detection of trace environmental contaminants, despite their low concentration in the medium.