Comprehensive two-dimensional gas chromatography in environmental non-targeted analysis

Accelerated industrialization processes have led to emerging contaminants (ECs) being increasingly recognized as critical environmental challenges. Certain ECs in the environment remain unmonitored or unidentified, and targeted analysis proves insufficient for achieving comprehensive and accurate characterization. In contrast to conventional one-dimensional gas chromatography (1D-GC), comprehensive two-dimensional gas chromatography (GC × GC) offers the benefits of a larger peak capacity, superior resolution, and enhanced sensitivity in analyzing organic compounds within environmental matrices. This study thoroughly summarizes the applicability and limitations of GC × GC using non-targeted analysis (NTA) in organic contaminants across various environmental matrices, including air, dust, particulate matter, aerosols, soil, sediment, sludge, water, biota, and multi-residues, over the period from 2010 to 2025. Utilizing the exceptional separation power of GC × GC technologies, comprehensive analyses of organic pollutants have been characterized, encompassing polycyclic aromatic hydrocarbons, volatile organic compounds, pesticides, halogenated organic compounds, etc. Identifying previously overlooked emerging contaminants supports the development of policies to control these pollutants. Additionally, progress in GC × GC modulator technology, mass spectrometry hyphenation, characteristics of NTA, and data processing approaches is comprehensively outlined. At the end of the review, it summarizes the limitations of GC × GC in matrices analysis and conducts an in-depth discussion on the NTA based on GC × GC regarding three aspects: the application of hyphenated technologies for full-range coverage, the implementation of AI-assisted data processing, and the need for unified standards.