Abstract: A capillary column comprising monodispersed particles. The capillary is formed using a suitable substrate, wherein two plates are bonded together. At least one of the plates comprises a channel where particle beads are housed. Particle bead positions are of defined and equivalent diameter are arranged along the longitudinal axis of the housing structure. These positions are used to position packing material used to occupy the column. The particle beads themselves are of equivalent diameter.

Abstract: A method for removing a target DNA fragment having a predetermined base-pair length from a mixture of DNA fragments comprises the following steps. A mixture of DNA fragments which may contain the target DNA fragments is applied to a separation column containing media having a nonpolar, nonporous surface, the mixture of DNA fragments being in a first solvent mixture containing a counterion and a DNA binding concentration of driving solvent in a cosolvent. The target DNA fragments are separated from the media by contacting it with a second solvent solution containing a counterion and a concentration of driving solvent in cosolvent which has been predetermined to remove DNA fragments having the target DNA fragment base pair length from the media. The target DNA fragments can be collected and optionally amplified. When the method is being applied to collect a putative fragment, if present, no DNA fragments having the base pair length of the target DNA could be present in the mixture.

Abstract: Nonporous beads having an average diameter of about 0.5-100 microns are suitable for chromatographic separation of mixtures of polynucleotides when the beads comprise a nonporous particle which are coated with a polymer or which have substantially all surface substrate groups endcapped with a non-polar hydrocarbon or substituted hydrocarbon group. The beads provide efficient separation of polynucleotides using Matched Ion Polynucleotide Chromatography.

Abstract: A method for removing an organic solute from a solution, comprising contacting the solution with a polymer formed by copolymerizing one or more hydrophobic monomers and one or more hydrophilic monomers, whereby the solute is adsorbed onto the polymer. The solution can comprise a polar solvent such as a polar organic solvent or water or an aqueous buffer. The hydrophobic monomer can be, for example, divinylbenzene. The hydrophilic monomer can be, for example, a heterocyclic monomer, such as a vinylpyridine or N-vinylpyrrolidone.

Abstract: Improved liquid chromatography systems having components made of titanium, stainless steel, or organic polymeric material are useful in the separation of polynucleotide fragments, particularly large fragments of double-stranded polynucleotides, by Matched Ion Polynucleotide Chromatography (MIPC). The titanium, stainless steel, or polymeric components are treated so that they do not release multivalent cations into aqueous solutions flowing through the chromatography system. Alternatively, or in addition to utilizing materials made of the components listed above, a multivalent cation capture resin placed upstream of the separation column can be employed to remove multivalent ions from the system. The multivalent cation capture resin can be contained in a guard disk, a guard column, or a guard cartridge.

Abstract: The present invention relates generally to mesoporous sorbent materials having high capacity, high selectivity, fast kinetics, and molecular recognition capability. The invention also relates to a process for preparing these mesoporous substrates through molecular imprinting techniques which differ from convention techniques in that a template molecule is bound to one end of bifunctional ligands to form a complex prior to binding of the bifunctional ligands to the substrate. The present invention also relates to methods of using the mesoporous sorbent materials, for example, in the separation of toxic metals from process effluents, paints, and other samples; detection of target molecules, such as amino acids, drugs, herbicides, fertilizers, and TNT, in samples; separation and/or detection of substances using chromatography; imaging agents; sensors; coatings; and composites.

Abstract: Chromatographic material having the general formula S-B-X-Y-L where S is a solid support, B is a binding group, X is a substantially non-ionic hydrophilic organic spacer, Y is a coupling group and L is an affinity ligand. The chromatographic material is substantially free of non-specific adsorption and is stable at high pH.

Abstract: Sample displacement chromatography is performed at low operating pressures (less than 30 bar) and/or at high sample loading (in excess of 500 mg/cm2 column area), with product recovery being effected in a non-gradient manner. The low operating pressures permit the use of simple and inexpensive apparatus. Non-gradient product recovery allows the desired product to be allowed in solutions with advantageously high concentration. Materials which may be purified include pharmaceuticals, pharmaceutical excipients, fine chemicals, biochemicals, X-ray contrast agents, chelating agents, peptides, proteins, oligonucleotides and vaccines. Apparatus embodiments include sample displacement chromatography apparatus comprising one or more ion exchange columns in direct combination with one or more desalting columns, and multicolumn chromatography apparatus permitting switching between a series separation mode and a parallel extraction mode.

Abstract: A method of using, in a reversed phase chromatography, a stationary phase including, as a main component thereof, an alkyl group having not less than 24 carbon atoms, with a mobile phase including water as a main component thereof. A reversed phase chromatograph apparatus for separating a water soluble compound, including a mobile phase comprising water as a main component thereof, and a stationary phase including, as a main component thereof, an alkyl group having not less than 24 carbon atoms.

Abstract: A method for purification of proteins by displacement chromatography in hydrophobic interaction and reversed phase chromatographic systems uses low molecular weight (less than about 10,000) surface-active compounds as displacers. Examples of effective displacers are benzethonium chloride, benzyltributylammonium chloride, and tetrahexylammonium chloride.

Abstract: The present invention provides monolithic polymer matrices for the separation of bio-organic molecules by liquid chromatography. In one embodiment, the matrix is formed from a polymerization mixture including (i) a hydrophobic monomer, (ii) a crosslinking agent, and (iii) a porogenic solvent or mixture of porogenic components. The monolithic matrices of the invention are particularly useful for resolving polynucleotides (e.g., DNA and/or RNA) in samples by way of reversed-phase ion-pairing chromatography.

Abstract: An electrospray device, a liquid chromatography device and an electrosprayliquid chromatography system are disclosed. The electrospray device comprises a substrate defining a channel between an entrance orifice on an injection surface and an exit orifice on an ejection surface, a nozzle defined by a portion recessed from the ejection surface surrounding the exit orifice, and an electrode for application of an electric potential to the substrate to optimize and generate an electrospray; and, optionally, additional electrode(s) to further modify the electrospray.

Abstract: An electrospray device, a liquid chromatography device and an electrosprayliquid chromatography system are disclosed. The electrospray device comprises a substrate defining a channel between an entrance orifice on an injection surface and an exit orifice on an ejection surface, a nozzle defined by a portion recessed from the ejection surface surrounding the exit orifice, and an electrode for application of an electric potential to the substrate to optimize and generate an electrospray; and, optionally, additional electrode(s) to further modify the electrospray.

Abstract: A system and method for electrochemically regenerated ion neutralization and concentration is disclosed. In one aspect of the invention, a system is provided comprising a HPLC column pump, a concentrator column, an analytical column, a suppressor, a detector, a mixed bed deionizing resin, a sample injector, and a neutralization cartridge.

Abstract: A method for separating a mixture of at least two chemical compounds which first involves loading and sintering a frit material in a capillary to form a first retaining frit. After removing substantially all unsintered frit material from the capillary, a packing material made up of a substrate coated with a linear carbohydrate polymer is loaded into the capillary adjacent to the first retaining frit to form a stationary phase. More frit material is loaded in the capillary and is sintered to form a second retaining frit adjacent to the packing material on the side opposite from the first retaining frit. Substantially all unsintered frit material is again removed from the capillary. The chemical mixture is then introduced into the capillary at one of the retaining frits, and migration of the mixture across the packing material is induced by applying a voltage across the capillary. Differences in electroosmotic flow velocity between the compounds cause them to separate during migration.

Abstract: Compositions and methods for selectively binding metal ions from a source solution comprise using a polyhydroxypyridinone-containing ligand covalently bonded to a membrane support having the formula M—A—L(HOPO)n. M is a membrane having a hydrophilic surface, A is a covalent linkage mechanism, L is a ligand carrier, HOPO is a hydroxypyridinone appropriately spaced on the ligand carrier to provide a minimum of six functional coordination metal binding sites, and n is an integer of 3 to 6. The separation is accomplished by passing a source solution containing the ions to be separated through a cartridge containing the membrane-ligand composition, causing the selected ions to be complexed to the HOPO ligands and subsequently removing the selected ions from the cartridge by passing an aqueous receiving solution through the cartridge and quantitatively stripping the selected ions from the HOPO ligand.

Abstract: A method for detecting a putative mutant DNA in a sample of DNA includes the steps of amplifying the sample of DNA using PCR; hybridizing the amplified sample to form a mixture of homoduplexes and heteroduplexes; separating the mixture into fractions by Denaturing Matched Ion Polynucleotide Chromatography; and blind collecting the eluted fractions at a retention time corresponding to the retention time of the heteroduplex. The DNA in the blind collected fractions can be PCR amplified to obtain an increased amount of heteroduplex relative to homoduplex. The method is useful for determining the remission status of a patient in which the tissue-derived DNA sample contains a large background of wild type or where the putative mutant DNA is below the limit of detection.

Abstract: The invention provides separating agents for optical isomers which have a high optical resolving power inherent in polysaccharide derivatives and high solvent resistance, and which can be produced through short process steps; a process for producing the same, and a method for separating optical isomers. The invention also provides separating agents for optical isomers, wherein the surface of a polysaccharide derivative supported on a carrier or the surface of a pulverized or granulated polysaccharide derivative is coated with a polymer, which are produced by supporting the polysaccharide derivative on the carrier and then coating the surface thereof with the polymer to thereby immobilize the polysaccharide derivative on the substrate, or by grinding or spheroidizing the polysaccharide derivative and then coating the surface thereof with a polymer.

Abstract: A process and apparatus for purifying one or more target substances from a source liquid, employing one or more cross-flow filter elements, and one or more types of chromatography resins, in combination, to provide purification with advantageous yield, product purity, and cost- and time-efficiency.

Abstract: An integrated suppressor and detector for suppressed ion chromatography includes a stationary phase, a fluid flow path, at least first and second regeneration electrodes, and at least first and second sensor electrodes. Methods of suppressed ion chromatography using the integrated suppressor and detector are also described.

Abstract: The present invention provides a computer method and apparatus for detecting mutations in DNA fragments. Specifically, percent acetonitrile and threshold temperature, for use in the denaturing high performance liquid chromatography method of separating DNA fragments, are determined. In a preferred embodiment, the present invention serves as a preprocessor to the DHPLC system described in the cited art.

Abstract: Improved liquid chromatography systems having components made of titanium, stainless steel, or organic polymeric material are useful in the separation of polynucleotide fragments, particularly large fragments of double-stranded polynucleotides, by Matched Ion Polynucleotide Chromatography (MIPC). The titanium, stainless steel, or polymeric components are treated so that they do not release multivalent cations into aqueous solutions flowing through the chromatography system. Alternatively, or in addition to utilizing materials made of the components listed above, a multivalent cation capture resin placed upstream of the separation column can be employed to remove multivalent ions from the system. The multivalent cation capture resin can be contained in a guard disk, a guard column, or a guard cartridge.

Abstract: Methods are disclosed for detecting the presence of at least two predetermined known materials in a test sample. At least one of the predetermined known materials is a control material. The test sample is introduced into a test column which has a snare for each predetermined known material. Each snare has a capture material specific to the associated predetermined known material, and the capture material will bind with the associated predetermined known material to form a bound material. The test column is then washed to remove any materials which have not been bound to the capture materials. Finally, the presence of bound materials is detected on each of the snares. The method is useful for pathogens, DNA and RNA.

Abstract: The invention recognizes the deleterious effects of trace, and even undetectable amounts of multivalent cations on the separation of mixtures of polynucleotides, especially double stranded polynucleotides, and provides an improved method for separating such mixtures on wide pore, non-polar separation media by eliminating multivalent cations from the all aspects of the separation process. This is accomplished by using components in the separation process which are materials which do not release metal cations. In addition, the use of cation capture resins and other methods to remove residual traces of multivalent cations from eluting solvents, sample solutions, separation media, and system components is described. It is also important to remove any traces or organic contaminants from solvents solutions and system parts.

Abstract: In order to regenerate a plurality of suppressors (6, 6a, 6b) that are inserted alternatingly into a device for ion-exchange chromatography, apart from an analysis branch (9), at least one additional treatment branch (10, 10a) is anticipated, through which a treatment agent (7, 7a) can be fed. The analysis branch (9) and the treatment branch (10, 10a) each possess a gap (34) in which the suppressors (6, 6a, 6b) can be alternatingly inserted. In order to insert a suppressor in a pipework branch, the suppressor is moved relative to the pipework branch until the connection openings (36a, 36b) of the suppressor are aligned with the corresponding pipe openings (35) of the gap of the pipework branch concerned.

Abstract: A system for separating compounds of relatively low molecular weight substantially not greater than about one kilodalton from compounds having relatively high molecular weights substantially an order of magnitude greater or more than the low molecular weight compounds in a liquid mixture. The system includes a chromatographic column packed with uniformly distributed rigid, solid, porous particles having chromatographically active, hydrophobic surfaces, average diameters of not less than about 30 .mu.m, and average pore diameters sufficiently small to substantially exclude introduction of the compounds of relatively high molecular weight into the pores. The mixture is pumped through the interstitial volume between the particles at a reduced velocity greater than about 5,000, until a band of the high molecular weight compounds exits the column. The low molecular weight compounds are then eluted and are recovered separately from the relatively high molecular weight compounds.

Abstract: Femtoliter to milliliter volumes of one or a plurality of different liquids are accurately dispensed electrokinetically without any direct electrical contact with such liquid(s). This is accomplished with apparatus which creates an electric field over dispensing receptacles to discharge such liquid(s) into receiver reservoirs or scientific apparatus. Two electrically-conductive plates are insulated from each other so that a field polarizes the liquid and forces movement without faradaic processes or joule heating. One of the plates is charged, whereas the other is grounded. Liquid to be dispensed is placed between the two plates and is dispensed on applying the charge to the charged plate.

Abstract: Described are preferred processes separating desired chemical products from impurities in solution utilizing thermally-managed chromatography over solid adsorbents. The preferred processes involve chromatographic principles which are assisted by varying the temperature of operation in separation and elution phases. Also described are processes for treating aqueous acids to dewater and recover the acids in an organic solvent such as an alcohol.

Abstract: The present invention provides a method for separating optical isomers, which enables the optical resolution of compounds which could not sufficiently be resolved optically by the reversed-phase chromatographic methods of the prior art. The present invention further provides a method for separating optical isomers by liquid chromatography with a separating agent comprising a polysaccharide derivative as the active component, which comprises conducting the chromatographic separation under the reversed-phase conditions by using a basic mobile phase.

Abstract: The invention concerns a process for the purification of factor VIII by affinity chromatography characterized in that a biological fluid containing factor VIII is contacted with immobilized cellular von Willebrand factor or a derivative thereof under such conditions that factor VIII is adsorbed to the immobilized von Willebrand factor or derivative thereof, impurities are separated and adsorbed factor VIII is eluted.

Abstract: This invention provides a immobilized receptors on supports in liquid chromatographic systems. The method of the invention provides means of evaluating the attachment of agents to receptors comprising the steps of:(a) immobilizing receptors on artificial membrane supports in a column,(b) exposing the supports with the receptors to test agents at varying concentrations in a liquid chromatographic system,(c) eluting the test agent from the column, and(d) evaluating the elution profile of the test materials from the column.Using this method, it is possible to evaluate the interaction of the test agent with the receptor. Following elution, it is possible to directly determine molecular structure by passing the elute through other testing devices such as a mass spectrometer.

Abstract: A process and apparatus for purifying one or more target substances from a source liquid, employing one or more cross-flow filter elements, and one or more types of chromatography resins, in combination, to provide purification with advantageous yield, product purity, and cost -and time-efficiency.

Abstract: An apparatus for effecting base pair length separations of DNA fragments by matched ion paired chromatography comprising a separation column containing separation media having non-polar DNA separation surfaces, separation solution supply means, and a separation solution conduit communicating with the separation column and the separation solution supply means, and a cleaning solution valve means positioned in the separation solution conduit for injecting cleaning solution into the separation solution conduit. A process for cleaning the non-polar DNA separation surfaces in the apparatus comprising interrupting the flow of separation solvent with a block of cleaning solution injected into the flow of separation solution passing to the column, the cleaning solution containing agent which removes accumulated residues from the non-polar surface. The cleaning solution can have an alkaline pH and contain a chelating agent such as EDTA.

Abstract: The present invention is directed to a method of determining the ratio of the concentration or amounts of two or more chemical compounds and/or biopolymers, or of the relative amounts of sub-populations of closely structurally related compounds, in a multi-component mixture, extract, system, and the like using an analytical physicochemical process. The method is based on distribution of the components of the mixture (system, extract, etc.) between two or more immiscible phases and the subsequent determination of the total amounts (concentrations) of biopolymers (chemical compounds) or of the amounts (concentrations) of one or more component(s) or sub-populations of the system in the phases. The ratio between these concentrations is defined therein as the partition coefficient. The partition coefficient is used as a measure of the ratio of the amounts of two or more biopolymers (chemical compounds) or their sub-populations in a multi-component mixture (extract, system, etc.

Abstract: A chromatographic process for separating racemic mixtures using a set of chiral stationary phases based on yohimbine and its derivatives has been developed. In particular, the hydroxyl functionality of yohimbine and its analogs is covalently bonded via a urethane linkage to a polymethylenesilyl chain attached to the bound hydroxyl groups of a refractory inorganic oxide by Si--O bonds. The resulting chiral stationary phases have multiple chiral recognition sites and can be used with a broad spectrum of materials as eluents without leaching.

Abstract: There is provided a packing material having a carrier coated with a substance having a separating capacity for high-performance liquid chromatography, wherein the performance of the packing material can be sufficiently exhibited with little dispersion of separating capacity thereof. The packing material contains part of a coating solvent remaining therein, whereby the excellent separating capacity of the packing material can be exhibited.

Abstract: The present invention provides for the convenient preparation, purification, use and re-use of capillary electrochromatography columns that employ polymer gel materials as the separation media. The problems associated with employing crosslinked polymer gels is overcome through the use of physically entangled polymer gels, which comprise, as polymerized units: 1) 5% to 80% by weight of an ionizable monomer; 2) 0.1% to 50% by weight of a monomer containing a retentive ligand; and 3) 10% to 80% by weight of a nonionic monomer.

Abstract: A system for separating compounds of relatively low molecular weight substantially not greater than about one kilodalton from compounds having relatively high molecular weights substantially an order of magnitude greater or more than the low molecular weight compounds in a liquid mixture. The system includes a chromatographic column packed with uniformly distributed rigid, solid, porous particles having chromatographically active, hydrophobic surfaces, average diameters of not less than about 30 .mu.m, and average pore diameters sufficiently small to substantially exclude introduction of the compounds of relatively high molecular weight into the pores. The mixture is pumped through the interstitial volume between the particles at a reduced velocity greater than about 5,000, until a band of the high molecular weight compounds exits the column. The low molecular weight compounds are then eluted and are recovered separately from the relatively high molecular weight compounds.

Abstract: A method for removing an organic solute from a solution, comprising contacting the solution with a polymer formed by copolymerizing one or more hydrophobic monomers and one or more hydrophilic monomers, whereby the solute is adsorbed onto the polymer. The solution can comprise a polar solvent such as a polar organic solvent or water or an aqueous buffer. The hydrophobic monomer can be, for example, divinylbenzene. The hydrophilic monomer can be, for example, a heterocyclic monomer, such as a vinylpyridine or N-vinylpyrrolidone.

Abstract: Epoxy resins, particularly those based on bisphenol A, can constitute the principal film forming polymer component of a storage stable autodepositable composition wherein the particle size distribution of all the film forming polymers in the composition satisfies certain criteria of size distribution, and an accelerator component which is an acid, oxidizing agent or complexing agent is present in amount sufficient to provide an oxidation-reduction potential at least 100 mV more oxidizing than a standard hydrogen electrode. Such dispersions can conveniently be prepared using a two stage process in which a solution of the film forming polymers is emulsified into water to form a preliminary dispersion and this preliminary dispersion is subjected to at least one particle size refinement stage in which the preliminary dispersion is forced through a narrow aperture.

Abstract: A method for the purification or recovery of immunoglobulins from plasma or other immunoglobulin-containing material is disclosed which includes subjecting the plasma or other immunoglobulin-containing material to chromatographic fractionation on a macroporous anion-exchange resin to recover an immunoglobulin-containing fraction therefrom.

Abstract: Process 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.

Abstract: An automatic variable-orifice fluid restrictor for use with a supercritical extractor having a collection trap or a supercritical chromatograph includes an inlet line for fluid at a pressure above its critical pressure, an extended tubular probe having an inner and an outer surface and a proximal and a distal end. The proximal end of the probe carries an inlet connected to the inlet line and is outside of the trap. The distal end of the probe includes a variable orifice means adapted for metering the fluid. The variable orifice means is adjacent to the outer surface of the probe and is located in the midst of the trap. The variable orifice means is adjusted by an adjusting stem having first and second ends. The first end of the adjusting stem is connected to automatic control means such as a servo at the proximal end of the probe and outside of the trap. The second end of the adjusting stem varies the area of the orifice by moving a first orifice member.

Abstract: The present invention is directed to novel methods for enhancing the ability to separate a species of interest from other different species present in a free solution mixture thereof which takes advantage of interactions that occur between soluble, small molecular weight ligands and the species of interest. The small molecular weight ligands employed in the present invention function to interact with a species of interest in a mixture of different species through either affinity, hydrophobic and/or ionic interactions, thereby altering the molecular weight, hydrodynamic volume and/or isoelectric point of the species of interest and rendering it separable from other component(s) in the mixture.

Abstract: A method and apparatus for increasing the current efficiency of suppressor and suppress-like pretreatment devices is disclosed for the purpose of suppressing a high concentration of eluent without the detrimental effects of excess heat generation. The method and apparatus may be used in ion chromatography.

Abstract: The invention relates to improved chromatographic support materials, to the preparation thereof and to the use thereof as sorbent for chromatography. The particles of these materials have hydrophobic surfaces consisting of fatty acid esters in the pores and hydrophilic outer surfaces. The materials according to the invention permit direct separation of protein-containing samples by means of reverse phase methods.

Abstract: The present invention provides in one aspect, a novel method for recovering an organic solute from a predominantly aqueous solution. In one embodiment, the solution is contacted with a dry, non-conditioned sorbent medium held by a supporting structure, whereby the solute is absorbed onto the matrix by hydrophobic interactions. A solvent is then passed through the medium, thereby desorbing the solute. Finally, the solute is collected. A further aspect of the invention provides water-wettable sorbent materials for use in solid phase extractions. Embodiments of polymer-based and silica-based sorbent materials are disclosed.

Abstract: Apparatus and method for improving the resolution of non-pressure driven capillary chromatographic systems, and particularly for capillary electrochromatography (CEC) systems. By reducing the cross-sectional area of a packed capillary column by means of a second open capillary contiguous with the outlet end of a packed capillary column, where the packed capillary column has a cross sectional area of between about 2 and 5 times that of the open capillary column, the phenomenon of band broadening in the transition region between the open capillary and the packed capillary column, where the individual components of the mixture are analyzed, can be eliminated, thereby providing for a significant improvement in resolution and more accurate detection and analysis.

Abstract: Non-polar polymeric separation media, such as beads or monoliths, are suitable for chromatographic separation of mixtures of polynucleotides when the surfaces of the media are unsubstituted or substituted with a hydrocarbon group having from one to 1,000,000 carbons and when the surfaces are substantially free from mutivalent cation contamination. The polymeric media provide efficient separation of polynucleotides using Matched Ion Polynucleotide Chromatography. Methods for maintaining and storing the polymeric media include treatment with multivalent cation binding agents.

Abstract: Nonporous beads having an average diameter of about 0.5-100 microns are suitable for chromatographic separation of mixtures of polynucleotides when the beads comprise a nonporous particle which are coated with a polymer or which have substantially all surface substrate groups endcapped with a non-polar hydrocarbon or substituted hydrocarbon group. The beads provide efficient separation of polynucleotides using Matched Ion Polynucleotide Chromatography.