Pyrolysis gas chromatography-mass spectrometry in environmental analysis: Focus on organic matter and microplastics

Pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) has great potential within environmental analysis. This technique is mainly used for the chemical identification of macromolecules that cannot be characterized by either liquid or gas chromatography due to their big size. Through pyrolysis (controlled thermal degradation), these macromolecules are broken down into simpler molecules that can be separated by gas chromatography and detected by mass spectrometry. This technique has been traditionally used in environmental samples for the characterization of organic matter and humic substances, contaminants, lignins, etc. It attains the identification of the different types of chemical units that integrate the macromolecules. In addition, recently, this technique has experienced an important boom in the chemical characterization of microplastics present in environmental samples. This has triggered its use in this type of matrix. We describe the fundamentals and modalities of Py-GC-MS and outline some of the recent applications for the environmental analysis with special emphasis on humic substances and/or other types of organic matter components as well as microplastics, but reporting also other interesting application of environmental relevance.