Preparation of Porous Silica Particles with a Controlled Mesopore Size by Ultrasonic Spray Drying for High-Performance Liquid Chromatography (HPLC)

Abstract

Highly spherical porous silica particles (PSPs) with a controlled pore size were prepared by ultrasonic spray drying and were used as a packing material for high-performance liquid chromatography (HPLC). By using organic additives added to the silica sol as porogens instead of low-melting salts, choosing the size of the colloidal SiO₂ particles, and varying the type and the ratio of additives, the pore size of the PSPs was finely tuned from 2.9 to 34.4 nm. Subsequently, PSPs having pore sizes of 7.4, 13.5, and 29.0 nm were modified by chlorodimethyloctadecylsilane (PSPs-C18), and HPLC columns packed with the different PSPs-C18 were evaluated systematically using aromatic compounds and alkylbenzene derivatives as probes. A plate number of 81,000/m and the relative standard deviation of less than 1% in the retention time were obtained for pentylbenzene over 100 injection and HPLC separation cycles for the 7.4-PSPs-C18 column. Five proteins were also separated within 25 min using the 29.0-PSPs-C18 column.

Keywords:

• Controlled pore size
• high-performance liquid chromatography (HPLC)
• porous silica particles
• ultrasonic spray drying

Acknowledgments

The authors express thanks to Professor Shaohua Huang for his helpful comments on the manuscript.

Disclosure statement

The authors declare no conflicts of interest.

Additional information

Funding

This work was supported by Natural Science Foundation of Zhejiang (LGG20B050001, 2019R02009, 2022C01029), Natural Science Foundation of Anhui (202003c08020001), Natural Science Foundation of Ningbo (2020Z036), and the K.C. Wong Magna Fund of Ningbo University.