Preparation and Evaluation of a New Calix[4]arene‐Bonded Stationary Phase for HPLC

Abstract

A new p‐tert‐butyl‐calix[4]arene‐bonded silica gel stationary phase (C4BS) was prepared via breaking ring reaction of 3‐glycidoxypropyltrimethoxysilane used as coupling reagent for high performance liquid chromatography (HPLC). The structure of the new stationary phase was characterized by Fourier transform infrared (FTIR) spectroscopy, elemental analysis, and thermal analysis. Its chromatographic property was evaluated by using neutral, acidic, and basic solutes as probes. Meanwhile, several bonded phases, such as a p‐tert‐butylphenyl‐ether‐bonded stationary phase (PEBS, the monomer‐bonded phase), a p‐tert‐butyl‐calix[8]arene‐bonded phase (C8BS), and ODS were also used for the comparative study of C4BS, under the same chromatographic conditions. The results show that C4BS is an excellent reversed‐phase packing with versatile chromatographic performance. The hydrogen bond, π–π and synergistic interactions between the calix[4]arene ligand of C4BS and solutes can be observed, which result in that the chromatographic property of the new packing is different from both PEBS and ODS, especially, the latter. Additionally, the steric selectivity is also an important factor in the separation of sulfonamides. C4BS exhibits fast analysis for hydrocarbons and high selectivity for the sulfonamides. However, typical inclusion complex contribution on the new packing cannot be expected, which might be because of its small cavity (3 Å) relative to C8BS (11.7 Å).

Keywords:

• High performance liquid chromatography
• Chromatographic evalution
• Retention mechanism
• P‐tert‐Butyl‐calix[4]arene‐bonded stationary phase

Acknowledgment

The authors gratefully acknowledge National Nature Science Foundation of China (Grant: 20275029), the Excellent Young Teachers Program of MOE, P.R. China.