Retention Slopes of Steroids on Gas Chromatography in a Series of Combination Columns

Previous results from this laboratory (1) have shown that when retention times of steroids are plotted against percent combination packing in gas chromatographic columns, different slopes are obtained for different compounds. The slopes of these lines evidently indicate the functional groups present in the steroid molecule. Since the number of steroids in the original series was small, it was desirable to increase the variety to obtain further insight concerning the functional group-slope relationship. Five different combinations of packings were used to study 75 steroids of four classes. Negative or positive slopes, depending on whether the functional groups were predominantly hydroxyl or ketonic, were found as predicted.