Experimental method to distinguish column dead time from system dead time for the accurate determination of gas chromatographic void volumes: simultaneous pre- and post-column injection

Abstract

A new experimental technique for the accurate determination of the dead time of a chromatographic column is described. The technique involves simultaneous pre- and post-column injections of an unretained probe solute. The method allows the accurate determination of the column void volume as opposed to the system void volume which includes extracolumn volumes. The procedure also eliminates the uncertainties in void volume measurements caused by splitters, multiple flow paths, or auxiliary gas flows required for some detectors or certain types of chromatography such as supercritical fluid chromatography.