Sol−Gel Poly(ethylene glycol) Stationary Phase for High-Resolution Capillary Gas Chromatography

Abstract

A sol-gel chemistry-based method was developed for the preparation of highly stable capillary gas chromatography (GC) columns with surface-bonded poly(ethylene glycol) (PEG) stationary phase. Through a single-step procedure, it concurrently provided column deactivation, stationary-phase coating, and chemical immobilization of the coated film. Sol-gel reactions were carried out within fused-silica capillaries that were filled with properly designed sol solutions containing two sol-gel precursors, two different triethoxysilyl-derivatized poly(ethylene glycol)s, two sol-gel catalysts, and a deactivation reagent. Hydrolytic polycondensation reactions led to the formation of a sol-gel coating chemically bonded to the inner walls of the capillary. A number of sol-gel coated fused-silica capillary columns were prepared using sol-gel-active PEG derivatives. These columns demonstrated many inherent advantages, the main being the strong anchoring of the coating to the capillary wall resulting from chemical bonding with the silanol groups on the fused-silica capillary inner surface. This chemical bonding yielded strongly immobilized PEG coatings with outstanding thermal stability (up to 320 degrees C). To our knowledge, such a high thermal stability has not been achieved so far on conventionally prepared PEG GC columns. Sol-gel PEG columns provided excellent chromatographic performances: high number of theoretical plates, excellent run-to-run and column-to-column reproducibility, and pronounced selectivity for a wide range of test solutes. Using n-octadecane as a test solute (k = 7.14), an efficiency value of 3200 theoretical plates/m was obtained on a 10 m x 0.25 mm i.d. fused-silica capillary column. Five sol-gel PEG columns provided RSD values of 1.09% for column efficiency (solute, n-octadecane), 1.37% for retention factor (solute, n-octadecane), and 0.9% for separation factor (for solute pair o- and p-xylene). In five replicate measurements using the same column, RSD values of less than 0.50% for the retention time and 1.36% for retention factor (k) were obtained.

Negatively charged sol‐gel column with stable electroosmotic flow for online preconcentration of zwitterionic biomolecules in capillary electromigration separations

“…Sol-gel chemistry [43,44] makes it possible to synthesize organic-inorganic hybrid materials with advanced properties using a single-step procedure. Columns prepared by sol-gel technologies offer many advantages over their conventional counterparts in GC [45,46], HPLC [47,48], and CE [29,34,35,41].…”

Preparation of stir bars for sorptive extraction using sol–gel technology

“…1A. The mechanism of the coating process, therefore, is not the same as reported before [21,22,27]. In order to increase the surface area and expose most of the Table 2 Peak height repeatability data for analytes and their detection limits…”

Investigation of biomembrane-drug interactions of different biomembranes by capillary electrophoresis

“…The sol-gel approach brings new promise to provide high stationary phase stability and column efficiency in liquid-phase separations. These early work stimulates further developments of the areas of sol-gel stationary phase in chromatographic [4][5][6] and electrophoresis separations [7][8][9] and sample preparation technologies.Biomembrane chromatography, which uses cell membrane of human or animal as a stationary phase, is an ideal technology for studying the interactions between drug and cell membrane, membrane receptor and enzyme. In this way, it retains best the integrity and enzymatic activity of cell membrane, the stereo-structure and surroundings of membrane receptor.…”