Methods for generating second dimension retention index data in comprehensive two-dimensional gas chromatography

Two methods of generating transportable second dimension retention data are outlined for comprehensive two-dimensional gas chromatography (GC×GC). They are both refinements of a previously outlined procedure, which adapted `isovolatile' curves to retention prediction maps developed in our laboratory, extended to a more polar homologous series, the linear primary alcohols. The earlier work investigated maps based on alkanes and methyl ketones and methyl esters; here the method of data collection to generate the retention map has also changed, extending the retention base range. The resulting retention map permits a retention basis to be used for GC×GC data, however, a more polar retention set than alkanes is required. The calculation of [`]retention indices' is aided by the generation of `fractional reference compound' curves, by either direct manipulation of data local to the solute, or generation of a discrete curve coincident with the retention co-ordinates of the target compound.