MicroQuechers-nanoliquid chomatography-nanospray-tandem mass spectrometry for the detection and the quantification of trace pharmaceuticals in benthic invertebrates

Due to industrialization and the use of chemical products ineveryday life,various types of drugs and pesticides are present in our environment, which threaten and cause negative impacts on aquatic ecosystems. The consequences of these pollutants are gradually becoming visible.Recent evidence confirms that long term exposure to environmental pharmaceutical concentrations can induce adverse effects in aquatic vertebrates and invertebrates such as reproductive impairments and collapse wild populations. Consequently,one of the challenges of environmental science is to evaluate the associated risks. In this context, a new methodology has been developed using nano-LC-nano-ESIMS/MS to quantify traces of two pharmaceuticals(a neuropharmaceutical drug, fluoxetine, and an anticonvulsant drug, carbamazepine) in two molluscs, Potamopyrgus antipodarum and Valvata piscinalis, which are both prosobranch gastropods. A simple and quick extraction method was developed based on amodified and miniaturized version of the QuEChERS method.The procedure involves the extraction o fapproximately 10mg of wet mollusc tissue by 500 mL of a mixture of acetonitrile/water/hexane(50/20/30)and100mg of buffer salt.Thus, the extraction step was carried out on an individual scale. The sensitivity of this method allowed for the detection of levels as low as18ng/g and 128ng/g for carbamazepine and fluoxetine, respectively,with recoveries of greater than 85% for the two targeted compounds. This method was then applied to both gastropod species exposed to fluoxetine under laboratory conditions.The results provide evidence of bioaccumulation in both P.antipodarum and V.piscinalis and reveal the inter-species differences.