retention volume (quality) retention volume (quality) Retention volume is the volume of the mobile phase required to elute a component the concentration of which in the stationary phase is negligible compared to that in the mobile phase. In other words, this component is not retained at all by the stationary phase. Thus, the hold-up volume is equal to the retention volume of an unretained compound. The hold-up volume includes any volumes contributed by the sample injector, the detector, and connectors. In gas chromatography this term is also called the gas hold-up volume. The corrected gas hold-up volume is the gas hold-up volume multiplied by the compression (compressibility) correction factor. [IUPAC] PAC, 1993, 65, 819 (Nomenclature for chromatography (IUPAC Recommendations 1993)) retention volume volume (quality)