4710 results about "Chromatographic separation" patented technology

High-performance liquid chromatography (HPLC) methods and systems are disclosed that combine parallel chromatographic separation of a plurality of samples with a detection technique that involves post-separation treatment of the plurality of samples to enhance one or more properties of the sample or of a component thereof, followed by detection of the one or more enhanced properties. Selective, tunable detection schemes are achievable, and are particularly advantageous as applied in connection with combinatorial chemistry, combinatorial material science and more particularly, combinatorial synthesis and screening of polymeric materials.

This invention relates to processes for the assembly of three-dimensional structures having periodicities on the scale of optical wavelengths, and at both smaller and larger dimensions, as well as compositions and applications therefore. Invention embodiments involve the self assembly of three-dimensionally periodic arrays of spherical particles, the processing of these arrays so that both infiltration and extraction processes can occur, one or more infiltration steps for these periodic arrays, and, in some instances, extraction steps. The product articles are three-dimensionally periodic on a scale where conventional processing methods cannot be used. Articles and materials made by these processes are useful as thermoelectrics and thermionics, electrochromic display elements, low dielectric constant electronic substrate materials, electron emitters (particularly for displays), piezoelectric sensors and actuators, electrostrictive actuators, piezochromic rubbers, gas storage materials, chromatographic separation materials, catalyst support materials, photonic bandgap materials for optical circuitry, and opalescent colorants for the ultraviolet, visible, and infrared regions.

Microfluidic devices with multiple fluid process regions for subjecting similar samples to different process conditions in parallel are provided. One or more common fluid inputs may be provided to minimize the number of external fluid supply components. Solid materials such as chromatographic separation media or catalyst media is preferably provided in each fluid process region. Solid materials may be supplied to the devices in the form of slurry, with particles retained by porous elements or frits. Different fluid process regions may having different effective lengths, different solid material types or amounts, or may receive different ratios of common fluids supplied to the device. The flow resistances of dissimilar fluid process regions may be balanced passively with the addition of impedance elements in series with each fluid process region.

Effective processes are provided for the production of xylitol and ethanol and other products from solutions derived from lignocellulose-containing material in biomass. The solutions can be hydrolyzed or partially hydrolyzed before being fermented with microbes. The fermented solution can be distilled and can be subsequently separated, such as, by chromatographic separation, membrane separation, etc. The recovered xylitol solution can be crystallized to provide pure xylitol crystals.

A material for chromatographic separations, processes for its preparation, and separation devices containing the chromatographic material. In particular, porous inorganic / organic hybrid materials are provided with a decreased concentration of surface organic groups. These particles may be surface modified and have enhanced stability at low pH.

An improved ion source and portable analyzer for collecting and focusing dispersed gas-phase ions from a reagent source at atmospheric or intermediate pressure, having a remote source of reagent ions generated by direct or alternating currents, separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and / or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques or probes containing samples are coupled to atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermospray ionization sources.

Novel chromatographic materials for chromatographic separations, columns, kits, and methods for preparation and separations with a superficially porous material comprising a substantially nonporous core and one or more layers of a porous shell material surrounding the core. The material of the invention is comprised of superficially porous particles and a narrow particle size distrution. The material of the invention is comprised of a superficially porous monolith, the substantially nonporous core material is silica; silica coated with an inorganic / organic hybrid surrounding material; a magnetic core material; a magnetic core material coated with silica; a high thermal conductivity core material; a high thermal conductivity core material coated with silica; a composite material; an inorganic / organic hybrid surrounding material; a composite material coated with silica; a magnetic core material coated with an inorganic / organic hybrid surrounding material; or a high thermal conductivity core material coated with an inorganic / organic hybrid surrounding material.

PCT No. PCT / SE97 / 00237 Sec. 371 Date Dec. 29, 1998 Sec. 102(e) Date Dec. 29, 1998 PCT Filed Feb. 14, 1997 PCT Pub. No. WO97 / 29825 PCT Pub. Date Aug. 21, 1997Process for separating off a peptide or a nucleic acid by an anion exchanger (I) characterized in that a) the anion exchanger (I) exhibits ligands, which (i) contain a primary, secondary or tertiary amino group and (ii) are covalently bound to an organic polymer (matrix), b) there on a carbon atom at a distance of 2 or 3 atoms away from an amino nitrogen in the ligands is a hydroxyl group or a primary, secondary or tertiary amino group, and c) the maximum elution ionic strength in the pH range 2-14 for at least one of the proteins transferrin, ovalbumin 1, ovalbumin 2, beta -lactoglobulin 1 and beta -lactoglobulin 2 on the anion exchanger is higher than the elution ionic strength required for a quaternary comparative ion exchanger.

Chromatographic separation devices include multiple batch-processed columns joined by a body structure and adapted to perform parallel analyses. Both slurry-packed and monolithic column embodiments are provided. One or more liquid-permeable frits of various types may be used to retain stationary phase material within columns. A fluidic distribution network may be used to distribute stationary phase material and / or mobile phase solvents to multiple columns. Separation devices, including microfluidic embodiments, may be fabricated with various materials including polymers. Multi-column fabrication and separation methods are provided.

An improved ion source for collecting and focusing dispersed gas-phase ions from a reagent source at atmospheric or intermediate pressure, having a remote source of reagent ions separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and / or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermospray ionization sources.

An improved ion source for collecting and focusing dispersed gas-phase ions from a reagent source at sub-atmospheric or intermediate pressure, having a remote source of reagent ions separated from a low-field sample ionization region by a barrier, comprised of alternating laminates of metal and insulator, populated with a plurality of openings, wherein DC potentials are applied to each metal laminate necessary for transferring reagent ions from the remote source into the low-field sample ionization region where the reagent ions react with neutral and / or ionic sample forming ionic species. The resulting ionic species are then introduced into the vacuum system of a mass spectrometer or ion mobility spectrometer. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to sub-atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermal-pneumatic ionization sources.

An improved ion source and means for collecting and focusing dispersed gas-phase ions from a remote reagent chemical ionization source (R2CIS) at atmospheric or intermediate pressure is described. The R2CIS is under electronic control and can produce positive, negative, or positive and negative reagent ions simultaneously. This remote source of reagent ions is separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the R2CIS into the low-field sample ionization region where the reagent ions react with neutral and / or ionic sample forming sample ionic species. The resulting sample ionic species are then introduced into a mass spectrometer, ion mobility spectrometer or other sensor capable of detecting the sample ions. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermospray ionization sources; and improving the sensitivity of chemical detectors or probes.

A process for manufacturing xylose by extracting hemicellulose from a cellulosic material, such as by a cold caustic extraction method, concentrating the extract, such as by nanofiltration, into a hemicaustic stream containing hemicellulose with greater than about 85 wt % xylan content, and subsequently hydrolysing the xylan from the hemicaustic stream to xylose. The high concentration of xylan within the concentrated hemicaustic stream enables hydrolyzation of the xylan to food-grade xylose and, optionally, hydrogenation of the xylose to xylitol without the need of a chromatographic separation step as previously required.

Novel material for chromatographic separations, processes for its preparation, and separations devices containing the chromatographic material. In particular, the disclosure describes porous inorganic / organic hybrid particles having a chromatographically-enhancing pore geometry, which desirably may be surface modified, and that offer more efficient chromatographic separations than that known in the art.

This invention relates to processes for the assembly of three-dimensional structures having periodicities on the scale of optical wavelengths, and at both smaller and larger dimensions, as well as compositions and applications therefore. Invention embodiments involve the self assembly of three-dimensionally periodic arrays of spherical particles, the processing of these arrays so that both infiltration and extraction processes can occur, one or more infiltration steps for these periodic arrays, and, in some instances, extraction steps. The product articles are three-dimensionally periodic on a scale where conventional processing methods cannot be used. Articles and materials made by these processes are useful as thermoelectrics and thermionics, electrochromic display elements, low dielectric constant electronic substrate materials, electron emitters (particularly for displays), piezoelectric sensors and actuators, electrostrictive actuators, piezochromic rubbers, gas storage materials, chromatographic separation materials, catalyst support materials, photonic bandgap materials for optical circuitry, and opalescent colorants for the ultraviolet, visible, and infrared regions.

The invention belongs to the technical field of the preparation of graphene quantum dots (GQDs), and particularly relates to a method for preparing fluorescent graphene quantum dots with controllable oxidation degree and fluorescence by a solvothermal method. According to the technical scheme, the method comprises the following steps of: 1, preparing graphene oxide; 2, preparing green fluorescent graphene quantum dots by a single-step method starting from the graphene oxide; and 3, preparing the fluorescent graphene quantum dots with the controllable oxidation degree by a column chromatographic separation method. According to the method, the sizes and surface oxidation degree of the graphene quantum dots can be controlled under the synthetic condition, so that the fluorescent properties and surface chemical characteristics of the graphene quantum dots are controlled. The prepared graphene quantum dots are high in chemical stability and biocompatibility, low in biotoxicity, and high in property of applicable upconversion fluorescence, matt and the like and bleaching performance. By the excellent properties, the graphene quantum dots have a wide application range in aspects of biological imaging, photovoltaic devices and sensors, and are novel promising fluorescent nano materials.

The present invention relates to biodegradable biocompatible polyketals, methods for their preparation, and methods for treating animals by administration of biodegradable biocompatible polyketals. In one aspect, a method for forming the biodegradable biocompatible polyketals comprises combining a glycol-specific oxidizing agent with a polysaccharide to form an aldehyde intermediate, which is combined with a reducing agent to form the biodegradable biocompatible polyketal. The resultant biodegradable biocompatible polyketals can be chemically modified to incorporate additional hydrophilic moieties. A method for treating animals includes the administration of the biodegradable biocompatible polyketal in which biologically active compounds or diagnostic labels can be disposed. The present invention also relates to chiral polyketals, methods for their preparation, and methods for use in chromatographic applications, specifically in chiral separations. A method for forming the chiral polyketals comprises combining a glycol-specific oxidizing agent with a polysaccharide to form an aldehyde intermediate, which is combined with a suitable reagent to form the chiral polyketal. A method for use in chiral separations includes the incorporation of the chiral polyketals in the mobile phase during a chromatographic separation, or into chiral stationary phases such as gels. The present invention further relates to chiral polyketals as a source for chiral compounds, and methods for generating such chiral compounds.

Novel compositions are disclosed for use as a stationary phase in chromatography comprising an inorganic substrate that is modified with at least one silane having the formula R1δ-Qα-(CH2)βSiR2γX3-γ. In a preferred embodiment, the inorganic substrate is silica gel and is modified with at least two silanes. Methods of preparation and use in chromatographic applications are disclosed. The novel compositions provide superior chromatographic performance, reduced silanol activity, enhanced stability, and reproducibility in preparation and performance.

The invention relates to liquid chromatography techniques for rapidly characterizing samples, such as polymer solutions, emulsions and dispersions, and to devices for implementing such techniques. The system includes a design that provides the ability to perform chromatographic separations by using mobile phase composition gradients and temperature gradients during separations. The invention accomplishes this by providing mixing zones for a plurality of fluids as well as heated and chilled feeds feeding the fluids to the mixing zones. Additionally, the system provides the ability to analyze separated components with a detector and / or collect separated fractions into vessels of a fraction collector for further separation and / or analysis.

The present invention provides novel chromatographic materials, e.g., for chromatographic separations, processes for their preparation and separations devices containing the chromatographic materials. The preparation of the inorganic / organic hybrid materials of the invention wherein a surrounding material is condensed on a porous hybrid core material will allow for families of different hybrid packing materials to be prepared from a single core hybrid material. Differences in hydrophobicity, ion-exchange capacity, surface charge or silanol activity of the surrounding material may be used for unique chromatographic separations of small molecules, carbohydrates, antibodies, whole proteins, peptides, and / or DNA.

An advanced silica gel sorbent for use in chromatographic separations that has been chemically modified by surface polycondensation of a trifunctional and / or difunctional organosilane. The chromatographic media exhibits a wider pH range and improved pH stability as compared to other silica gel based sorbents, while retaining all other positive aspects attributed to silica gel based sorbents. A method of forming the advanced silica gel sorbent by Templated Multilayer Inorganic / Organic Grafting.

The invention relates to a method for separating and purifying mussel mucin by using a mixed adsorption chromatography. Mussel mucin contains a group of L-3,4- -Dihydroxyphenylalanine (L-DOPA), a phenohydroxyl group thereof can act as the supplier for hydrogen bond, the benzene ring thereof can generate a hydrophobic effect, and the lysine thereof with strong positive charges is capable of forming a static bond. On the basis of the properties of mussel mucin, a mixed adsorption chromatography (i.e. the adsorption chromatography based on three principles of adsorption with hydrogen bond, adsorption with hydrophobic effect, and static adsorption) is adopted to overcome the problem of low yielding rate of mussel mucin in the prior art for separating and purifying mussel mucin. An strong acid extraction is adopted to eliminate small-molecular compounds from a desalting column, an argar medium with high concentration and high cross-linking degree to separate and purify mussel mucin, and an acetic acid-urea- polyacrylamide gel electrophoresis is used to differentiate mussel mucin through specific chromogenesis with nitro blue tetrazolium. Three principles adopted with one separation medium to separate mussel mucin achieve high selectivity, simplify the purification technology, and decrease production cost.

A method for analyzing a sample of double stranded DNA to determine the presence of a mutation therein comprises contacting the sample with a mutation site binding reagent, and chromatographically separating and detecting the product. The chromatographic separation can be performed using Matched Ion Polynucleotide Chromatography, size exclusion chromatography, ion exchange chromatography, or reverse phase chromatography. The mutation site binding reagent can be an enzyme or a non-proteinaceous chemical reagent. In one embodiment, a mutation site binding reagent binds to the site of mutation and alters the chromatographic retention time. In another embodiment, a mutation site binding reagent cleaves at the site of mutation, resulting in an increase in the number of fragments.

The invention relates to methods for isolating an analyte of interest in a sample suspected of containing the analyte of interest using two-dimensional planar electrochromatography. The methods comprise treating at least a portion of the sample with a mobility modifier capable of modifying the mobility of the analyte of interest after the second dimension of planar electrochromatography. Kits and compositions are also disclosed.