Research Publications
Preparation and characterization of organo-silica monoliths for applications in liquid chromatography
Research Objectives
The main objective of this research is to engage science majors in the preparation of various monolithic separation media for applications in capillary liquid chromatography. The specific aims of the project are:
- In situ sol–gel synthesis of porous silica, alumina, and hybrid monoliths
- Surface modification of monoliths via thermal- and photografting
- Application of the prepared monoliths in reversed-phase microflow liquid chromatography
Particle-packed columns have been used for more than a century to separate components of chemical mixtures in high-performance liquid chromatography (HPLC). Over the past two decades, a trend has emerged toward improving the speed of analysis, with the goal of achieving sufficient analyte resolution in the shortest possible time. High-throughput analyses are essential for the rapid screening of large numbers of samples in fields such as drug discovery and environmental analysis.
Our research focuses on monolithic columns, which have been introduced as an alternative to particle-packed columns. Monoliths offer several advantages, including lower back pressure and enhanced diffusional mass transfer. Our work is directed toward the preparation and characterization of inorganic monolithic materials such as silica, alumina, and organic–silica hybrids. These materials are further modified via thermal – or photografting. By selecting different monomers, we can tailor the surface chemistry of the synthesized monoliths.
These materials are prepared within fused silica capillaries and evaluated for their chromatographic performance using microflow liquid chromatography. The range of compounds suitable for separation includes simple organic molecules as well as proteins and peptides. Many types of laboratories can benefit from these materials, including chemical, biological, pharmaceutical, medical, industrial, and environmental laboratories.
Undergraduate researchers will gain:
- Hands-on experience in the preparation and characterization of monolithic columns. Capillary preparation is low-cost, safe, and requires a minimal number of synthetic steps.
- An understanding of the principles of sol–gel transitions and inorganic chemistry that govern the formation of highly porous monoliths.
- Proficiency in grafting techniques.
- Chromatographic skills through the operation and troubleshooting of a liquid chromatograph.
- An understanding of fundamental separation principles in liquid chromatography, based on observing changes in chromatographic behavior of test mixtures with different polymeric coatings.
- An appreciation for green chemistry principles. Capillary liquid chromatography operates at flow rates in the µL/min range (rather than mL/min), thereby minimizing the amounts of solvent and analyte required for analysis.
- Preparation of research reports and manuscripts and presentation of research at scientific meetings.
