History: from GC-GC to GCxGC
Two-dimensional gas chromatography GC-GC and GCxGC

One-dimensional gas chromatography (1D-GC or simply GC) is routinely used to analyze volatile compounds in mixtures of varying complexity. When coupled with a universal detector such as a flame ionization detector (FID) or mass spectrometer, each compound detected can be quantified or even identified. However, the complex nature of some samples often requires lengthy analysis, and complete separation of all constituents is sometimes impossible. Indeed, the co-elution of analytes may come into play, and this can be an obstacle to a complete qualitative and quantitative analysis, despite the use of powerful analytical techniques such as mass spectrometry.

To solve the problem of peak co-elution, two-dimensional gas chromatography (GC-GC) was introduced in the 1960s