Abstract
In order to apply the Kováts' equation to partially methylated alditol acetates, we investigated the correlation between their molecular structures and retention indices from their relative retention times in gas-liquid chromatography. Many partially methylated alditol acetates were expressed in their numerical values based on two cardinal numbers, (fully methylated glucitol: 0, and fully acetylated glucitol: 100). Retention indices I and increment H were given by following equation:
I=100×log TX-log TM/log TA-log TM,
H=Ia-Ia, Ha=0.99×Hb+c.
We used 5 index units, three various methylated positions and two interactions. Relative retention times of acetates were obtained by calculation with several index units and by experiment on a column of 10 % SE-30/Chromosorb W (180°C and 210°C). Since we found the index units of the configurational contribution had additivity, it was possibe to apply the units to partially methylated alditol acetates. Using several calculated indices, we could presume a relative retention time of partially methylated alditol acetates which were difficult to synthesize. Moreover, it has become feasible to deduce the structure of unknown alditol acetates from their relative retention times.