Gas chromatography. V. The relationship between retention data and molar volume A simple relationship, which could be used for the correlation and identification of organic and organosilicon materials in the analysis of mixtures was derived from the laws for the chromatographic separation of compounds. The logarithm of the retention data for members of a homologous series of organic compounds (those materials which have the same structure but contain different numbers of the same organic groups or halogen atoms, or organic compounds with similar structural properties (halogenorganic compounds)) is linearly proportional to the molar volume ▪ where V g is specific retention volume, V M is molar volume, and k 1 , k 2 are constants. The graphic representation of this relationship is a straight line whose slope is characteristic for each individual organic and organosilicon group of compounds. This relationship was verified with organic and organosilicon compounds. The relationship was applied to the gas chromatoraphic separation of the low-molecular-weight organosilicon compounds, for the purpose of identification.