Towards the comprehensive wide-scope analysis of legacy and emerging contaminants sorbed in microplastics

Microplastics (MPs) are dangerous pollutants, not only considered dangerous due to the risk of their ingestion by living organisms in affected ecosystems, but also because they have the ability to release additives, used in their manufacture, in addition to their capability to concentrate pollutants from the surrounding environment. Monitoring the organic contaminants sorbed in MPs is currently an analytical challenge on which there is still no agreement in the scientific community. Thus, this work aims to develop and validate two analytical methods fulfilling the SANTE analytical quality control guidelines and the principles of white chemistry for the simultaneous determination of a wide range of organic contaminants by liquid chromatography-high-resolution mass spectrometry (LC-HRMS) and gas chromatography-mass spectrometry (GC-MS), in three plastic matrices. Of the 86 compounds quantified from 88 by GC-MS, up to 96 % were fully and partially validated in the polymers whereas in the case of the 189 compounds quantified from 254 by LC-HRMS, the percentage of fully and partially validated compounds was 92 %, allowing the detection down to 0.1 ng/g. The multi-residue methodologies also provide suitable environmental sustainability, as well as high practicability allowing high-throughput analysis of large batches of samples which might set the basis for extending the chemical coverage on the analysis of contaminants sorbed by MPs. This work presents a guide for the comprehensive determination of legacy and emerging contaminants sorbed by MP using LC-HRMS and GC-MS, in accordance with the holistic perspective of the white chemistry, which might help to extend the chemical coverage and knowledge in the field of plastic pollution.