Microplastic and Nanoplastic Analysis: From Pyrolysis Gas Chromatography-Mass Spectrometry to Pyrolysis Two-dimensional Gas Chromatography-Mass Spectrometry—A Critical Review

The growing environmental and health concerns regarding micro- and nanoplastics (MNPs) have prompted the development of advanced analytical methods for accurate characterization and quantification. Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) enables polymer identification by their thermal destruction into characteristic fragments. However, the small particle size and interferences originating from complex sample matrices complicate its analysis. Therefore, the integration of comprehensive two-dimensional GC (GC×GC) would improve separation efficiency and sensitivity and provide a detailed composition of environmental and biological samples. This review documents (i) the evolution of Py-GC-MS and (ii) the potential to resolve overlapping compounds, improving quantification accuracy, and detecting minor plastic compounds and degradation byproducts by comprehensive GC×GC-MS as a crucial approach to measure MNPs. Despite the documented advancements, key challenges persist. The lack of standardized protocols for sample preparation and calibration, impeding the comparability of studies, is of prime concern. The massive presence of (in)organic interferences even further accentuates the absence of internal standards in terms of quantification. Therefore, to improve analytical reliability, future research should focus on developing standardized methodologies, improving detection sensitivity for NPs, and incorporating complementary approaches. Additionally, coupling GC×GC with time-of-flight MS further strengthens its capability to provide higher analytical resolution power and better chemical description of pyrolyzates. This review highlights the crucial role of advanced Py and chromatography-based techniques in supporting the analytical description of the extent of plastic pollution and in supporting evidence-based policymaking and successful mitigation efforts to protect ecosystems and public health.