Comparative investigation of the retention behaviour of nucleoside derivatives on alumina stationary phases in thin-layer chromatography and high-performance liquid chromatography

The retention of 21 natural and synthetic deoxyuridine derivatives was determined by high-performance liquid chromatography (HPLC) using an aluminum column with water—2-propanal or dichloreothane-methanol mobile phases in various volume ratios. The log k′ (capacity factor) values from HPLC were compared with the RM [log(1/RE — 1)] values determined by thin-layer chromatography (TLC) on aluminuma layers using water—2-propanol or dichloreothane—methanol mobile phases. The highest correlation coefficient (0.93) between the log k′ values and the RM values was obtained when dichloroethane-methanol-acetic acid (50:50:0.01) and 100% water were used as mobile phases both in TLC and HPLC, respectively. It was found that the retention of the nucleoside derivatives did not depend linearly on the concentration of the stronger component in the mobile phase. The length of the alkyl chain of the substituent at position 5 of the deoxyuridine has a negligible impact on the retention. The presence of the double and triple bounds in the substituent, however, significantly influenced the retention properties of nucleosides on alumina layers. Principal component analysis proved that the reverwed phase (water—2-propanol) and adsorption eluents (dichloroethane—methanol) show different selectivity.