Chapter 6 Comprehensive Two - Dimensional Gas Chromatography ( Gc × Gc )

Comprehensive two-dimensional gas chromatography (GC × GC) is one of the most powerful analytical tools for the analysis of organic compounds in complex matrices. The technique is based on continuous collection of the effluent from a GC column and periodic reinjection of small portions of the effluent to a second column of different properties. The process is repeated at a rate fast enough that each peak eluting from the first column is sampled at least three times. In this way, the separation achieved in the first column is preserved, and additional separation in the second column is accomplished. At the heart of any GC × GC system is an interface, which physically connects the primary and the secondary columns and allows the periodic collection/injection to occur. Raw data obtained from a GCxGC run have to be converted from the linear form to a 2-D representation using special software algorithms. GC × GC finds applications in many areas, including petroleum analysis, environmental analysis, forensics, atmospheric chemistry, etc.