GCxGC
Encyclopedia
Two-dimensional gas chromatography, or GCxGC was originally described in 1991 by Professor Phillips and his student Liu. Since then the GC × GC has been extensively applied to solve complex problems of separations. Some of the most well-established research groups in the world that are found in Australia, Italy, Holland, Canada,http://www.science.uwaterloo.ca/~tgorecki/ United States, and Brazil.
The time required to complete a cycle is called the period of modulation, which typically lasts between 2 to 10 seconds is related to the time needed for the compounds are eluted in 2D.
Another key aspect of GC x GC that can be highlighted is that the effluent from the re 1D, which occurs during the modulation, causes a significant increase in sensitivity. The modulation process causes the chromatographic bands in GC × GC systems are 10-50 times closer than in 1D-GC, resulting in values for 2wb between 50 ms to 500 ms, which requires detectors with fast response and Small internal volumes.
Modulation: The process
In GC × GC two columns are connected sequentially, typically the first dimension is a conventional column and the second dimension is a fast GC type, with a modulator positioned between them. The function of the modulator can be divided into basically three processes:- continuously collect small fractions of the effluent from 1D, ensuring that the separation is maintained in this dimension;
- focus or refocus the effluent of a narrow band;
- to quickly transfer the 2D fraction collected and focused as a narrow pulse. Taken together, these three steps is called modulation cycle, which is repeated throughout the chromatographic run.
The time required to complete a cycle is called the period of modulation, which typically lasts between 2 to 10 seconds is related to the time needed for the compounds are eluted in 2D.
Another key aspect of GC x GC that can be highlighted is that the effluent from the re 1D, which occurs during the modulation, causes a significant increase in sensitivity. The modulation process causes the chromatographic bands in GC × GC systems are 10-50 times closer than in 1D-GC, resulting in values for 2wb between 50 ms to 500 ms, which requires detectors with fast response and Small internal volumes.