Biocompatible solid-phase microextraction coupled to liquid chromatography triple quadrupole mass spectrometry analysis for the determination of phthalates in marine invertebrate

This paper describes the development and validation of a new procedure for the determination of phthalates in marine invertebrates, based on biocompatible solid-phase microextraction (BioSPME) followed by liquid chromatography coupled to mass spectrometry. The importance of this application relies on the current use of marine organisms as bioindicators for microplastic contamination through the detection of phthalates in their tissues. Challenges originate from the availability and/or possible restriction on the use of the biological materials, the need for user- friendly procedures for simplifying and speeding up operations in the marine environments, and the ubiquitous presence of phthalates in the laboratory environments that may cause background contamination. BioSPME served as an effective solution to all these issues, owing to the extreme minimization of the sample manipulation. Sampling operations were limited to the direct transfer of small amounts of the biological materials (150 mg) inside glass vials capped with aluminium lids; extractions were carried out by ultrasonication in acetone followed by dilution in ultrapure water and BioSPME clean-up; Electrospray (ESI) LC-MS/MS was employed for the final analytical determinations on the purified extracts. Tests were carried out on samples belonging to three different phyla, namely Cnidaria, Porifera, and Mollusca obtained from Maldivian coral reef environments and used for a current microplastic contamination biomonitoring project. Overall, very good sensitivity and repeatability, with negligible back contamination of the blanks were observed. The limits of detections were between 0.2 and 2.1 ng/g and precision, calculated as relative standard deviation (RSD), was below 14% for all the tested phthalates.