Abstract: A dual ligand sol-gel sorbent and method of manufacture is provided herein. The dual ligand sol-gel sorbent provides superior enrichment effects through simultaneous exploitation of superhydrophobicity of one of the ligands and the ability of the other ligand to undergo ?-? interaction with hydrophobic aromatic analytes. Sorbent performance is enhanced both in terms of analyte enrichment and sorbent stability, such as pH stability and solvent stability.

Abstract: The subject invention concerns metal or metalloid oxide-based sol-gel hybrid sorbent and methods of synthesis. In one embodiment, the sorbent is a ZrO2 polypropylene oxide based sol-gel. The subject invention also concerns a hollow tube or capillary internally coated with a sorbent of the invention. Sorbent coated tubes and capillaries of the invention can be used in extraction and/or enrichment of samples to be analyzed for catecholamines and related compounds.

Abstract: The subject invention concerns metal or metalloid oxide-based sol-gel hybrid sorbent and methods of synthesis. In one embodiment, the sorbent is a ZrO2 polypropylene oxide based sol-gel. The subject invention also concerns a hollow tube or capillary internally coated with a sorbent of the invention. Sorbent coated tubes and capillaries of the invention can be used in extraction and/or enrichment of samples to be analyzed for catecholamines and related compounds.

Abstract: Ionic liquid (IL)-mediated sol-gel hybrid organic-inorganic materials present enormous potential for effective use in analytical microextraction. One obstacle to materializing this prospect arises from high viscosity of ILs significantly slowing down sol-gel reactions. A method was developed which provides phosphonium-based, pyridinium-based, and imidazolium-based IL-mediated advanced sol-gel organic-inorganic hybrid materials for capillary microextraction. Scanning electron microscopy results demonstrate that ILs can serve as porogenic agents in sol-gel reactions. IL-mediated sol-gel coatings prepared with silanol-terminated polymers provided up to 28 times higher extractions compared to analogous sol-gel coatings prepared without any IL in the sol solution.

Abstract: Germania-based sol-gel organic-inorganic hybrid coatings were prepared for on-line coupling of capillary microextraction with high-performance liquid chromatography. A germania-based sol-gel precursor, tetra-n-butoxygermane and a hydroxy-terminated triblock copolymer, poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide), were chemically anchored to the inner walls of a fused silica capillary (0.25 mm I.D.). Scanning electron microscopy images of the sol-gel germania triblock polymer coating were obtained to estimate the coating thickness. The analyte distribution constants between a sol-gel germania organic-inorganic hybrid coating and the samples (Kcs) were determined. For a variety of analytes from different chemical classes, including polycyclic aromatic hydrocarbons (PAHs), ketones, alcohols, phenols, and amines, the Kcs values ranged from 1.8×101 to 2.0×104. The sol-gel germania triblock polymer coatings survived exposure to high temperature solvent conditions (200° C.

Abstract: A capillary column (10) includes a tube structure having inner walls (14) and a sol-gel substrate (16) coated on a portion of inner walls (14) to form a stationary phase coating (18) on inner walls (14). The sol solution used to prepare the sol-gel substrate (16) has at least one baseline stabilizing reagent and at least one surface deactivation reagent resulting in the sol-gel substrate (16) having at least one baseline stabilizing reagent residual and at least one surface deactivating reagent residual. A method of making the sol-gel solution is by mixing suitable sol-gel precursors to form the solution, stabilizing the solution by adding at least one baseline stabilization reagent, deactivating the solution by adding at least one surface deactivation reagent to the solution, and reacting the solution in the presence of at least one catalyst.

Abstract: Ionic liquid (IL)-mediated sol-gel hybrid organic-inorganic materials present enormous potential for effective use in analytical microextraction. One obstacle to materializing this prospect arises from high viscosity of ILs significantly slowing down sol-gel reactions. A method was developed which provides phosphonium-based, pyridinium-based, and imidazolium-based IL-mediated advanced sol-gel organic-inorganic hybrid materials for capillary microextraction. Scanning electron microscopy results demonstrate that ILs can serve as porogenic agents in sol-gel reactions. IL-mediated sol-gel coatings prepared with silanol-terminated polymers provided up to 28 times higher extractions compared to analogous sol-gel coatings prepared without any IL in the sol solution.

Abstract: Ionic liquid (IL)-mediated sol-gel hybrid organic-inorganic materials present enormous potential for effective use in analytical microextraction. One obstacle to materializing this prospect arises from high viscosity of ILs significantly slowing down sol-gel reactions. A method was developed which provides phosphonium-based, pyridinium-based, and imidazolium-based IL-mediated advanced sol-gel organic-inorganic hybrid materials for capillary microextraction. Scanning electron microscopy results demonstrate that ILs can serve as porogenic agents in sol-gel reactions. IL-mediated sol-gel coatings prepared with silanol-terminated polymers provided up to 28 times higher extractions compared to analogous sol-gel coatings prepared without any IL in the sol solution.

Abstract: The present invention provides germania-silica-based sol-gel monoliths that form the solid-phase material for extraction, isolation, preconcentration, and separation of analytes. In one embodiment, the germania-silica-based sol-gel monolith can be used to coat surfaces of the inner walls of extraction and chromatographic columns. In a preferred embodiment, the sol-gel germania-silica monolith of the present invention is formed from hydrolysis and polycondensation of precursors comprising tetraethoxygermane, tetramethoxysilane, and polyethylene glycol. Also provided are methods of preparing the germania-silica-based sol-gel monolith of the present invention.

Abstract: A method of preparing a sol-gel monolithic column includes the step of forming a separation bed (14) from a sol-gel solution in a single process step. This column has improved characteristics for CEC based on its incorporated surface charge and ease of operation due to a lack of or need for end frits. Also, a second type of column includes an optical window (30) for on-column detection.

Abstract: Germania-based sol-gel organic-inorganic hybrid coatings were prepared for on-line coupling of capillary microextraction with high-performance liquid chromatography. A germania-based sol-gel precursor, tetra-n-butoxygermane and a hydroxy-terminated triblock copolymer, poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide), were chemically anchored to the inner walls of a fused silica capillary (0.25 mm I.D.). Scanning electron microscopy images of the sol-gel germania triblock polymer coating were obtained to estimate the coating thickness. The analyte distribution constants between a sol-gel germania organic-inorganic hybrid coating and the samples (Kcs) were determined. For a variety of analytes from different chemical classes, including polycyclic aromatic hydrocarbons (PAHs), ketones, alcohols, phenols, and amines, the Kcs values ranged from 1.8×101 to 2.0×104. The sol-gel germania triblock polymer coatings survived exposure to high temperature solvent conditions (200° C.

Abstract: A novel on-line method is presented for the extraction and preconcentration of amino acids using a sol-gel coated column coupled to a conventional UV/vis detector. Extraction, stacking and focusing techniques are used in the preconcentration procedures. Sol-gel coatings are created by using N-Octadecyldimethyl[3(trimethoxysilyl)proply]ammonium chloride (C18-TMS) in the coating sol solutions. The resulting sol-gel coating carries a positive charge. For extraction, the pH of the samples is properly adjusted to impart a net negative charge to amino acids. A long plug of the sample is then passed through the sol-gel coated capillary to facilitate extraction via electrostatic interaction between the positively charged sol-gel coating and the negatively charged amino acid molecules. The focusing of the extracted amino acids is accomplished through desorption of the extracted amino acid molecules carried out by local pH change. The described procedure provides 150,000-fold enrichment effect for alanine.

Abstract: The present invention provides sol-gel germania-coated chromatography separation columns with improved stability under extreme pHs and high temperatures. Also provided are methods of preparation and uses of the sol-gel germania-coated separation columns of the present invention.

Abstract: The present invention provides germania-silica-based sol-gel monoliths that form the solid-phase material for extraction, isolation, preconcentration, and separation of analytes. In one embodiment, the germania-silica-based sol-gel monolith can be used to coat surfaces of the inner walls of extraction and chromatographic columns. In a preferred embodiment, the sol-gel germania-silica monolith of the present invention is formed from hydrolysis and polycondensation of precursors comprising tetraethoxygermane, tetramethoxysilane, and polyethylene glycol. Also provided are methods of preparing the germania-silica-based sol-gel monolith of the present invention.

Abstract: A method of preparing a sol-gel monolithic column includes the step of forming a separation bed (14) from a sol-gel solution in a single process step. This column has improved characteristics for CEC based on its incorporated surface charge and ease of operation due to a lack of or need for end frits. Also, a second type of column includes an optical window (30) for on-column detection.

Abstract: A method of preparing a sol-gel monolithic column includes the step of forming a separation bed (14) from a sol-gel solution in a single process step. This column has improved characteristics for CEC based on its incorporated surface charge and ease of operation due to a lack of or need for end frits. Also, a second type of column includes an optical window (30) for on-column detection.

Abstract: A method is presented describing in situ preparation of the titania-based sol-gel PDMS coating and its immobilization on the inner surface of a fused silica microextraction capillary. Sol-gel titania-poly (dimethylsiloxane) (TiO2-PDMS) coating was developed for capillary microextraction (CME) to perform on-line preconcentration and HPLC analysis of trace impurities in aqueous samples. The sol-gel titania-based coatings demonstrated strong pH stability and enhanced extraction capability over other commercially available GC coatings. Extraction characteristics of a sol-gel titania-PDMS capillary remained practically unchanged after continuous rinsing with a 0.1 M NaOH solution (pH=13) for 12 hours.

Abstract: A method is presented describing in situ preparation of the titania-based sol-gel PDMS coating and its immobilization on the inner surface of a fused silica microextraction capillary. Sol-gel titania-poly (dimethylsiloxane) (TiO2-PDMS) coating was developed for capillary microextraction (CME) to perform on-line preconcentration and HPLC analysis of trace impurities in aqueous samples. The sol-gel titania-based coatings demonstrated strong pH stability and enhanced extraction capability over other commercially availble GC coatings. Extraction characteristics of a sol-gel titania-PDMS capillary remained practically unchanged after continuous rinsing with a 0.1 M NaOH solution (pH=13) for 12 hours.

Abstract: The subject invention concerns zirconia-based hybrid organic-inorganic sol-gel coating for optional use as a stationary phase in capillary microextraction (CME), gas chromatographic (GC), high performance liquid chromatography (HPLC), capillary electrophoresis (CE), capillary electrochromatography (CEC) and related analytical techniques. Sol-gel chemistry is employed to chemically bind a hydroxy-terminated silicone polymer (polydimethyldiphenylsiloxane, PDMDPS) to a sol-gel zirconia network. In one embodiment, a fused silica capillary is filled with a properly designed sol solution to allow for the sol-gel reactions to take place within the capillary. In the course of this process, a layer of the evolving hybrid organic-inorganic sol-gel polymer becomes chemically bonded to the silanol groups on the inner capillary walls.

Abstract: A novel on-line method is presented for the extraction and preconcentration of amino acids using a sol-gel coated column coupled to a conventional UV/vis detector. Extraction, stacking and focusing techniques are used in the preconcentration procedures. Sol-gel coatings are created by using N-Octadecyldimethyl[3(trimethoxysilyl)proply] ammonium chloride (C18-TMS) in the coating sol solutions. The resulting sol-gel coating carries a positive charge. For extraction, the pH of the samples is properly adjusted to impart a net negative charge to amino acids. A long plug of the sample is then passed through the sol-gel coated capillary to facilitate extraction via electrostatic interaction between the positively charged sol-gel coating and the negatively charged amino acid molecules. The focusing of the extracted amino acids is accomplished through desorption of the extracted amino acid molecules carried out by local pH change. The described procedure provides 150,000-fold enrichment effect for alanine.