Rapid microwave-assisted extraction method for the analysis of common antidepressants and metabolites in marine organisms

Presence of antidepressants in aquatic environments could cause adverse effects even at low concentrations. Most published works have detected them in wastewater, and only a few have paid attention to the aquatic organisms that receive these polluted waters. This work presents the development, optimisation and application of an analytical method for the extraction and determination of four widely used antidepressants (venlafaxine, cit-alopram, sertraline, fluoxetine) and two metabolites (o-desmethylvenlafaxine, norsetraline) from fish tissue by microwave-assisted extraction and ultra high-performance liquid chromatography coupled to tandem mass spectrometry. To demonstrate the applicability of the method, it was validated in different marine organism species (fish, echinoderm, mollusc and algae). Under optimal conditions, recovery ranged between 70 and 120 % and deviation was lower than 20 % in most cases, depending on the species and the tested concentration. As no strong matrix effect was found, applying a clean-up step was unnecessary, although quantification was per -formed in real samples by matrix-matched calibration. Method quantification limits ranged between 2.32 and 196 ng g-1. Overall, this methodology proved to be a versatile method applicable to different species with good results. The developed analytical method was successfully applied to the extraction and determination of the target compounds from fish taken from offshore aquaculture cages in seawater (Canary Islands). Three main antidepressants were detected, but only two could be quantified: citalopram: 5.83 ng g-1 and sertraline: 6.58 ng g- 1.

Automated summary

The presence of antidepressants in aquatic environments can have adverse effects on organisms, even at low concentrations. This study developed an analytical method for extracting and determining antidepressants from fish tissue, and validated its applicability in various marine species. The method showed good recovery and quantification results, making it versatile and reliable.