Publication Date

Spring 2010

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

Advisor

Joseph J. Pesek

Keywords

Aqueous Normal Phase Chromatography, Carbohydrates, Amino acids, Organic acids, Fluorinated Stationary Phases, HPLC-ELSD

Subject Areas

Chemistry, Analytical; Chemistry, General; Chemistry, Organic

Abstract

Silica-based fluorinated bonded stationary phases have shown enhanced selectivity with altered elution orders for molecules differing in hydrophobicity and hydrophilicity in comparison with C8 and C18 reversed phase columns. Hence, two novel silica hydride-based fluorinated bonded phases have been synthesized using a hydrosilation

procedure to exploit fluorine-based unique selectivity for polar basic metabolites. Bonded moieties have been characterized by elemental and spectral analyses. Silica hydride-based aqueous normal phase (ANP) chromatography has retention behavior similar to normal phase chromatography, except for the use of water as a part of the binary solvent (>60 % acetonitrile : water). In ANP, a higher percentile of nonpolar mobile phase shows increased retention for acids and bases, and nonpolar solutes can also be retained as in reversed phase chromatography (RPC). The synergistic effects of fluorinated phases' altered selectivity and aqueous normal phase retentivity have been

explored for small polar metabolites using high performance liquid chromatography (HPLC) coupled with several detectors. Hydride-based fluorinated stationary phases showed good stability and remarkable reproducibility in retention time with %RSD < 1.

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