HPLC of some nucleosides and bases on p-tert-butyl-calix[6]arene-bonded silica gel stationary phase

The high-performance liquid chromatographic behavior of some nucleosides and bases was studied on a new p-tert-butyl-calix[6]arene-bonded silica gel stationary phase. The effect of mobile phase variables, such as ionic strength, methanol content, and pH on their chromatographic behavior was investigated. Some nucleosides and bases were successfully separated on the new stationary phase. Their retention behavior was compared with that on both Zorbax C-18 phase and-(ethylenediamino)propyltriethoxylsilane-bonded silica gel. The results indicate that the new stationary phase behaves as a reversed-phase packing, but its hydrophobicity is much weaker than that of Zorbax C-18 phase. The retention mechanism on the new stationary phase was also discussed.