Hold-up time in gas chromatography .1. New approach to its estimation

A new procedure to reach a good estimate of the hold-up time value (t(M)) in gas chromatography is presented. The value of t(M) obtained lies close to the experimental retention time of neon, the gas which has shown the shortest retention time in the columns studied. The new method, based on the retention of n-alkanes, is easily applied with any personal computer and may be used with detectors which do not respond to permanent gases. The procedure is reliable, produces very reproducible hold-up times and the value of t(M) obtained may be safely used to calculate both chromatographic and thermodynamic parameters.