Study of the Retention Characteristics of Calix[4]arene‐bonded Silica Stationary Phase and Comparison with Common Phases for HPLC Using Linear Solvation Energy Relationships

Abstract

The similarities and differences in retention characteristics of p‐tert‐butyl‐calix[4]arene‐bonded and three other silica‐based phases have been elucidated by the use of linear solvation energy relationships (LSERs). These phases were investigated in a common mobile phase. The results of LSERs on p‐tert‐butyl‐calix[4]arene‐bonded phase shows resemblances and differences to other silica‐based reversed‐phases. The retention of solutes on all the silica‐based phases are dominated by two factors: the solute size and hydrogen bond acceptor basicity. But, for p‐tert‐butyl‐calix[4]arene‐bonded phase, the main retention governing factor is the solute size, which contribution accounts for 63% of the variance in log k values. The s coefficient is small, but positive, which is unlike the common reversed phase stationary phases. The r coefficient, which is small and positive, showed the new phase has greater π–π interaction to solutes than all other phases, and relatively high selectivity to polyaromatic hydrocarbons. The retention mechanism of the phase, mainly, is a partitioning mechanism.

Keywords:

• HPLC
• Linear solvation energy relationships (LSERs)
• p‐tert‐Butyl‐calix[4]arene–bonded silica stationary phase
• Retention characteristics
• Reversed‐phases
• Solute molecular volume

Acknowledgment

This work was supported by the National Natural Science Foundation of China. Project number 20275018.