Programmed temperature gas chromatography ptgc

The above consequences of isothermal operation may be largely avoided by using the technique of programmed-temperature gas chromatography (PTGC) in which the temperature of the whole column is raised during the sample analysis. 

A branch of gas chromatography, known as programmed temperature gas chromatography (PTGC), allows one to vary the temp of the column during an analysis. The method is described in Refs 70a, 77 99(Compare with Item I)... 

In isothermal GC, peak width increases linearly with retention time and retention time increases exponentially with carbon number in a homologous series. In contrast, the peak width remains constant in programmed-temperature gas chromatography (PTGC) and retention times increase only linearly with carbon number in a homologous series. ... 

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