Comprehensive two-dimensional gas chromatography–mass spectrometry

Comprehensive two-dimensional gas chromatography (GC×GC)–mass spectrometry (MS) is currently the most powerful tool for analysing GC-amenable compounds. The technique is complemented by using MS as a third dimension, after two stages of chromatographic separation. In this Primer, various aspects of GC×GC–MS are explored, including basic principles and method optimization with both cryogenic and flow modulation. State-of-the-art instrumentation and data processing tools are discussed, including the advantages and limitations of GC×GC–MS compared with other GC techniques. A range of applications are explored, with an overall future outlook for the field. Information is provided on when and why GC×GC–MS should be used, how it can be fully exploited and potential advances that may occur in the next decade.