volume void volume void volume In liquid chromatography, the interparticle volume is equal to the mobile-phase hold-up volume (V_M) in the ideal case, neglecting any extra-column volume. [IUPAC] A void volume is the volume occupied by the mobile phase between the particles in the packed section of a column. [IUPAC] In gas chromatography, the symbol V_G may be used for the interparticle volume of the column. In the ideal case, neglecting any extra-column volume, V_G is equal to the corrected gas hold-up volume (V0_M). V_G = V0_M = V_M [IUPAC] V0 interstitial volume interparticle volume of the column