Contribution to the theory of the retention index system

Topological analysis of gas-liquid chromatographic behavior of alkenes

“…Although this precision could be improved by various means, we have not done so in order to simplify the structural model, and thereby the first physicochemical exploitation by topological analysis, as much as possible. To justify this we cite two examples we have published recently: for a population of 70 is 3.0 IU; for a population of polar compounds, 36 dibromoalkanes, the standard deviation is 3.6 IU (24). In addition, these standard deviations can be reduced by additional structural parameters.…”

Petroleum

“…The use of the Kovats retention indexes, or some variation of this system, seems to have become the most popular method for correlating GC retention times. Takacs and Szita (1921) developed a method to calculate retention indexes of paraffin hydrocarbons on the basis of their molecular structure. The method, based on the Kovats system, calculated the retention index of a saturated aliphatic hydrocarbon by treating it as the sum of the molecular index contribution (which equals the atomic index and the bond index contributions) and an index of interaction with the stationary phase.…”

Gas chromatography

“…The theory of FIory-Huggins or Miller-Guggenheim was applied to calculation of retention indices (942), and correlations were made with solute molecular structure (752,895). The temperature coefficient of I was evaluated as a new parameter in the identification of GC peaks (806) and the use of "zero point indices" (retention index extrapolated to 0 °K) was recommended (1, 892).…”