A Comparative Study of Methods for Determining Gas Hold-Up Time.

It has been proved mathematically that there exists an identity between the various published methods for determining the hold-up times in gas chromatography. All of these methods are based on the equation: ln t'R = ln (tR – tM) = a + bZ, where tR, t'R, and tM are retention times, adjusted retention times, and hold-up times, respectively; a and b are coefficients that depend on the experimental conditions, and Z is the numbers of carbon atom of a homologue. So long as there are no errors in the values of the retention times, the hold-up times obtained by different methods based on this equation will be the same. The calculated results of experimental data reported in the literature support the viewpoints presented here. [ABSTRACT FROM AUTHOR]