Mass spectrometry-based techniques for determination of microplastics in terrestrial ecosystems

Microplastics are becoming increasingly prevalent as pollutants in terrestrial habitats around the world. However, knowledge of their determination methods has not been standardized. Mass spectrometry, as a complementary technique to spectroscopy, could not only break the size limitation of microplastics, but also provide comprehensive information on morphologies and in situ distributions in terrestrial environments once coupled to an imaging system. A comprehensive evaluation is required to introduce the characteristics of mass spectrometry-based approaches, including their principles, strengths/weaknesses and suitable scopes of application. Thermal analysis coupled with gas chromatography mass spectrometry as the most commonly used techniques can result in a complete breakdown of polymers and conduct complicated analysis, while liquid chromatography-tandem mass spectrometry is effective for detecting trace microplastics analysis (cf μg/kg) in complicated terrestrial ecosystems. The novel time-of-flight mass spectrometry has significant promise for thorough investigation of microplastics (e.g., abundance, shape, type, etc.) particularly being equipped with imaging equipment. As a result, the study contributes to gaining a better understanding of the potential and limitations of mass spectrometry-based analytical protocols for measuring microplastic concentrations in terrestrial environments, as well as provide a valuable view on the suitable selection for mass spectrometry-based techniques in land systems.