Most HPLC columns are packed with silanol-rich (Si-OH) type-B silica material that often participates in undesired electrostatic interactions with the analyte solutes and produces poor peak shape [1,2]. These silanols are also known to facilitate surface hydration necessary for HILIC retention mode for polar analyte molecules. However, the hydrated surface composition can easily fluctuate, and thus results in a poor reproducibility and requires lengthy equilibration step. In this study, four novel stationary phases have been developed by using the TYPE-CTM Silica Hydride material, which has replaced up to 95% of the surface silanols with silicon-hydride (Si-H) groups. One of the advantages of this material is the ability to retain polar molecules by operating in adsorption-based aqueous normal phase (ANP) mode, despite of the surface coverage by hydrophobic Si-H group [4]. Overall, TYPE-CTM materials eliminate most of the drawbacks observed in the earlier forms of silica. The objectives of this study are three-fold: (1) to develop novel hydride-based columns by surface functionalization, (2) to evaluate the general chromatographic performances and analyte selectivity by HPLC-DAD and ESI- TOF-MS instrumentation, and (3) to explore new bioanalytical applications of the silica hydride stationary phases and ANP chromatography. Here, practical applications of the novel hydride-based columns were demonstrated in several research projects. The following topics are discussed in this seminar: the analysis of cannabinoids along with other psychoactive-substances[5], metabolomics characterization of the USDA grape cultivars, and method development for the ANP-coupled HDX-MS assay which will be used in the future structural proteomics studies.

References:

1 Snyder, L. S.; Kirkland, J. J.; Glajch, J. L. Practical HPLC Method Development, 2nd ed. New York: John Wiley & Sons, 1997.

2 Brown, L.; Ciccone, B.; Pesek, J. J.; Matyska, M. T. An Evolution in Separation Media for HPLC. American Lab. 2003, 35 (24), 23-29.

3 Sandoval, J. E.; Pesek, J. J. Hydrolytically Stable Bonded Chromatographic Phases Prepared through Hydrosilylation of Olefins on a Hydride-Modified Silica Intermediate. Anal. Chem. 1991, 63 (22), 2634-2641.

4 Pesek, J. J.; Matyska, M. T. A Comparison of Two Separation Modes: HILIC and Aqueous Normal Phase Chromatography. LCGC North America. 2007, 25 (5), 480-490.

 Synthesis and Evaluation of Novel Silica Hydride-based Stationary Phases for Bioanalytical Applications

5 Watanabe, S., Santos, T. Q., Matyska‐Pesek, M. T., & Pesek, J. J. Evaluating novel silica hydride‐based stationary