SEPARATION OF NUCLEOSIDES AND THEIR BASES BY REVERSED-PHASE LIQUID-CHROMATOGRAPHY USING PURE WATER AS THE MOBILE-PHASE

A new reversed-phase liquid chromatographic (RP-LC) method for the sep aration of nucleosides and their bases using pure water as the mobile phase is described, A conventional octadecylsilica (ODS) stationary ph ase was used and modified with strong-positively/strong-negatively cha rged zwitterionic surfactants, When ODS is modified in this manner, hy drophobic interactions between the stationary phase (ODS) and the anal ytes (nucleosides and their bases) are reduced dramatically. Subsequen tly, if pure water is used for the mobile phase then an 'effective' di stribution of the analytes between the stationary phase and the mobile phase can be achieved, It is proposed that the ODS is subjected to el ectrostatic fields produced by the positive and the negative charges i n the strong zwitterionic surfactant. Furthermore, the hydrophobic int eractions between the ODS and the analytes are greatly reduced by the electrostatic interactions emanating from these electrostatic fields. The practical applications of this and the possible mechanisms involve d are described and discussed in this paper. (C) 1997 Elsevier Science B.V.