Abstract: In order to investigate the quantitative structure-retention relationship in gas chromatography (GC), the molecular structure of monosubstituted alkane RX (X=halogen, OH, SH, NH2) is divided into two parts, R and X, to obtain molecular structure parameters, and the retention times in GC for 37 monosubstituted alkanes RX were determined. It was proposed that the retention time in GC is affected by three main factors for RX compounds, alkyl group R, substituted group X, and interaction between R and X. Using four parameters, the eigenvalue of bonding orbital-connection matrix EVM, the polarizability effect index of alkyl group PEI, the mass content for substituted group X, and the partial charge ΔNH on hydrogen atom of the group X, a quantitative structure-retention correlation model with correlation coefficient (r) of 0.9948 and standard deviation (S) of 0.0991 was obtained for the 37 RX compounds. The model obtained has good predictive and extrapolation ability. The predicted retention indexes are in good agreement with the experimental ones for alcohols.

Key words: monosubstituted alkanes , bonding orbital-connection matrix, polarizability effect index, quantitative structure-retention relationship, substructure, gas chromatography