University of South Florida

Other

Abdul John Malik

James Donald Hayes

David P Fries

Wen Li

Anne M Shearrow

Emre Seyyal

Scott S Segro

Chetan Shrikant Shende

Erica B Turner

Abdullah Awadh Alhendal

Tae-Young Kim

Dongxin Wang

Abuzar Kabir

A method of coating at least one silica capillary using a novel dual ligand sol-gel sorbent and method of manufacture of such sorbent 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 &#x3c0;-&#x3c0; 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.

Dual ligand sol-gel sorbent combining superhydrophobicity and &#x3a0;-&#x3a0; interaction

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 &#x3c0;-&#x3c0; 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.

Dual ligand sol-gel sorbent combining superhydrophobicity and &#x3c0;-&#x3c0; interaction

The subject invention concerns metal or metalloid oxide-based sol-gel hybrid sorbent and methods of synthesis. In one embodiment, the sorbent is a ZrOpolypropylene 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.

Metal oxide-based biocompatible hybrid sorbent for the extraction and enrichment of catecholamine neurotransmitters and related compounds, and method of synthesis

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. This study shows that IL-generated porous morphology alone is not enough to provide effective extraction media: careful choice of the organic polymer and the precursor with close sol-gel reactivity must be made to ensure effective chemical bonding of the organic polymer to the created sol-gel material to be able to provide the desired sorbent characteristics.

Method of making ionic liquid mediated sol-gel sorbents

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 (K) were determined. For a variety of analytes from different chemical classes, including polycyclic aromatic hydrocarbons (PAHs), ketones, alcohols, phenols, and amines, the Kvalues ranged from 1.8&#xd7;10to 2.0&#xd7;10. The sol-gel germania triblock polymer coatings survived exposure to high temperature solvent conditions (200&#xb0; C.) with little change in extraction capabilities. Reproducibility of the method for preparation of the sol-gel germania triblock polymer coatings was also evaluated, and the capillary-to-capillary RSD values ranged from 5.3% to 6.5%. The use of higher flow rates in extraction was found to significantly reduce the time required (from 30-40 minutes to 10-15 minutes) to reach equilibrium between the sol-gel germania triblock polymer coating and the analytes in the sample solution.

Materials and methods for capillary microextraction in combination with high-performance liquid chromatography comprising a sol-gel germania triblock polymer

A capillary column () includes a tube structure having inner walls () and a sol-gel substrate () coated on a portion of inner walls () to form a stationary phase coating () on inner walls (). The sol solution used to prepare the sol-gel substrate () has at least one baseline stabilizing reagent and at least one surface deactivation reagent resulting in the sol-gel substrate () 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.

High efficiency sol-gel gas chromatography column

Ionic liquid mediated sol-gel sorbents

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.

Germania-silica-based sol-gel monolith and uses thereof

A method of preparing a sol-gel monolithic column includes the step of forming a separation bed () 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 () for on-column detection.

Sol-gel monolithic column with optical window and method of making

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 (C-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.

Sol-gel coatings for on-line preconcentration in capillary electrophoresis

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) (TiO-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.

Titania-based coating for capillary microextraction

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 (C-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.

Method of using sol-gel coatings for on-line preconcentration of amino acids in capillary electrophoresis

The present invention provides for a column for use in capillary electrochromatography including a tube, wherein the tube includes an inner surface having a positively or negatively charged, chemically-bonded stationary coating thereon. The present invention further provides for a method of making a column for use in capillary electrochromatography, including a tube, wherein the tube includes an inner surface having a positively or negatively charged chemically-bonded stationary coating thereon, wherein the steps include filling the column with a sol-gel solution, maintaining the sol-gel solution within the column, and forcing the sol-gel solution out of the column with an inert gas. Further, the present invention provides for a method of analytical separation with a column including an inner layer having a positively charged chemically-bonded stationary coating thereon that reverses the direction of electroosmotic flow in the column compared with a column without the positive surface charge. Additionally, the present invention provides for a method of using a column including an inner layer of positively charged chemically-bonded stationary coating thereon by introducing a sample into the column operating under reversed electroosmotic flow due to positively charged chemically-bonded stationary coating.

Sol-gel open tubular ODS columns with charged inner surface for capillary electrochromatography

A method of preconcentrating trace analytes is accomplished by extracting polar and non-polar analytes through a sol-gel coating. The sol-gel coating is either disposed on the inner surface of a capillary tube or disposed within the tube as a monolithic bed.

Growing community of inventors

Tampa, FL, United States of America

Abdul John Malik