Retention behaviour of estradiol derivatives in reversed phase HPLC

Retention behaviour ofestradiol derivatives has been studied by the reversed phase HPLC. LiChrosorb RP-18 column end eluents consisting of methanol respectively aceto-nitrile and water in various proportions, were used. It was shown that there is a linear relationship between the retention constant and the volume fraction of organic component in the mobile phase. The slopes and intercepts of lines are in agreement with the polarity of derivatives studied. Considerable effect on the chromatographic behaviour exerted the type and position of substituents in the molecule of estradiol derivative. Results obtained in these investigations are compared with results of the same derivatives obtained in previous investigations on octadecyl silica gel in TLC with eluent methanol-water in various proportions.