Abstract: Methods of separating and classifying the relative amounts of two or more classes of hydrocarbon molecules in a sample are disclosed wherein an input stream comprising a mobile phase and the sample is injected into a chromatographic column, and an effluent stream exiting a chromatographic column is split into a first effluent stream and a second effluent stream. The mass of carbon in each of the classes of hydrocarbons in the first effluent stream is determined, preferably using a flame ionization detector, and the second effluent stream is directed through a variable restrictor, allowing the pressure and mass flow rate of the input stream to be independently controlled and improved results obtained. In a preferred embodiment the present invention also includes identifying the hydrocarbon molecules in the second effluent stream in order to verify the analysis or provide additional data, preferably by using an ultraviolet detector.

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: A fluid distributing-collecting system for a device for bringing fluids and solids into contact comprising several distributor plates and several panels for mixing, distributing or extracting fluids. The system comprises at least one level 1 chamber in connection with the outside of said device with at least one hose and, at least one level 2 chamber that is linked with the level 1 chamber and that comprises one or more connecting hoses of a selected length that are arranged in at least one zone. The zone is identified relative to an angle .alpha. relative to a radius of a plate and corresponds to a given angle sector, whereby said hose lengths, angle .alpha. and the angle sector are selected so that the injected fluid arrives approximately at the same time on all of the panels of the same plate. This system is used for separation of paraxylene in a simulated moving bed.

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: 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 device comprises at least one column 1 that is filled with a number of beds A.sub.n, whereby each bed A.sub.i is separated from the next bed A.sub.i+1 by a fluid distributor plate P.sub.i. Each plate is divided into a number of sectors P.sub.10, and P.sub.11, and each sector comprises at least two fluid distribution chambers CH.sub.i and CH.sub.j. Each chamber of the plate is connected to a transfer line LT.sub.i and LT.sub.j to the outside. Transfer line LT.sub.i, which is associated with chambers CH.sub.i of a distributor plate, is connected to transfer line LT.sub.j, which is associated with chambers CH.sub.j of the same plate, via a bypass line L.sub.i,j. The latter comprises means 14, 15, 16, and 17 for controlling and adjusting the flow rate of fluid that circulates there, such that each distribution chamber CH.sub.i is flushed by a fluid that is obtained from chamber CH.sub.j and that has approximately the same composition as that of the fluid that circulates through distributor plate P.sub.

Abstract: A system allows routine coupling of HPLC separations to sheathless .mu.-ESI sources for MS analysis. Characteristics of this system include stable electrospray throughout the HPLC gradient at low and high flow rates, lower background than conventional sources, and control over the width of eluting HPLC peaks without degradation of HPLC performance. This system includes a pre-column solvent flow splitter, a metal union in the split waste line for application of .mu.-ESI voltage, a divert valve containing two different size restrictors for control of flow, and pulled fused silica capillaries as .mu.-ESI emitters. The pulled tips allowed stable operation of the system with column flow rates ranging from ca. 5->250 nL/min.

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: A process for separating at least one component of a mixture in a set of closed-loop chromatographic columns is described, whereby the loop comprises at least one feedstock injection point, a raffinate draw-off point, an eluant injection point, and an extract draw-off point, in which a determination is made between an injection point and a draw-off point or vice-versa a chromatographic zone, and at the end of a given period of time, all of the injection and draw-off points are shifted by one column or column section in a given direction that is defined relative to that of the flow of a main fluid that circulates through the loop. During the period, the shifting of different injection and draw-off points of a column or column section is done at different times in such a way that the lengths of the zones that are defined by said different points are variable. The process is useful for the seperation particularly of stereoisumers for pharmaceuticals.

Abstract: The invention encompasses systems for column-based separations, methods of packing and unpacking columns and methods of separating components of samples. In one aspect, the invention includes a method of packing and unpacking a column chamber, comprising: a) packing a matrix material within a column chamber to form a packed column; and b) after the packing, unpacking the matrix material from the column chamber without moving the column chamber.

Abstract: A chromatography column having at least one central slurry valve positioned at either the top cell assembly and/or the bottom cell assembly. The central slurry valves have a pneumatically actuated valve sleeve which can be shifted to create two different flow configurations. One flow configuration allows for the simultaneous cleaning in place of the flow path used to charge the column with chromatography media and the separate processing of fluid through the chromatography media. The other flow configuration permits the reslurrying and removal of chromatography media from the column, and the subsequent repacking of the column with fresh chromatography media without disassembling the column and the provision of venting the column in the event of overpressurization during packing.

Abstract: The device comprises at least one column 1 that is filled with a number of beds A.sub.n having an adsorbent that are separated by a fluid distributor plate P.sub.1. Each plate is divided into a number of sectors P.sub.10 and P.sub.11, and each sector comprises at least one fluid distribution chamber 13 that is pierced with openings and a circulation space 8 in the vicinity of the openings. The chambers of the plate are connected to a line 10 for transfer to the outside. With respect to the chambers on a plate, transfer line 10 P, is connected to another transfer line 20 relative to chambers 23 on another plate (P.sub.i+1 or P.sub.i+2) that is arranged downstream by a bypass line L.sub.1,2. The latter comprises means 14, 15, 16 for monitoring and adjustment of the flow of fluid that circulates there, such that the distribution chambers are flushed by a fluid which has approximately the same composition as that of the fluid that circulates through circulation space 8 at each of the chambers.

Abstract: Disclosed is a device for a simultaneous multiple isolation and purification of nucleic acids from biological material based on binding nucleic acid to mineral carrier particles. The device includes a square-shaped plastic case, a shaking apparatus with sample vessels, and a shielding for the motor and shaking apparatus.

Abstract: A fraction collection system for liquid chromatography includes a conduit, which directs a sample eluent from an LC column through a flow splitter to a destructive analytical detector such as a mass spectrometer to analyze sample components, and to a fraction collector. A nondestructive detector such as a photodetector is positioned near the fraction collector to detect arrival of sample components. Optionally, a nondestructive detector such as a photodetector is situated upstream from the splitter, to detect passing sample components. Time intervals between detection of a calibrant or a sample component at any two of the detectors provide for automatable identification of selected sample components at the sample collector.

Abstract: A chromatographic simulated moving bed separation process is most generally characterized by a recycling pump which successively adopts the flow rate characteristics of 4 or 5 zones of the process. The invention describes the method by which a conventional simulated moving bed separator process can be adapted to a simulated moving bed process in which the recycling pump is operated at an optimal constant flow rate. In order to achieve this, throughout the cycle all the introduction and extraction circuits are shifted using independent means, such that the eluted volume at the outlet to each zone remains substantially constant, zone by zone, between two successive shifts throughout the cycle.

Abstract: Process for controlling the pressure in a separation system comprising a loop including several zones defined by fluid injection and fluid draw-off points is disclosed. A parameter such as the pressure is controlled at least at one point of the loop by acting on the global difference (.delta.) between the flow rates of fluids injected and the flow rates of fluids drawn off by means of well-determined variations (.delta..sub.X) applied to at least two injected and/or drawn off flows rates. This control is performed for example by imposing on each of these flow rates, variations (.delta..sub.X) depending on the respective values of these flow rates, and for example variations proportional to the respective values (X) of these flow rates. It is for example possible to maintain one or two of the flow rates of fluids injected and drawn off constant. The process can be applied for separating aromatic hydrocarbons or optical isomers for example.

Abstract: The invention relates to a method for the fractionation of molasses using a chromatographic simulated moving bed system in which the liquid flow is effected in a single direction in a system comprising at least two chromatographic partial packing material beds. In the method of the invention, the product or products are recovered during a multi-step sequence comprising the following phases: feeding phase of molasses, eluting phase and recycling phase. The liquid present in the partial packing material beds with their dry solids profile is recycled in the recycling phase in a loop comprising one, two or several partial packing material beds.

Abstract: Injection or extraction device that comprises at least one injection or extraction rail 2 that is integral with a chamber 1 for injecting a fluid F2 into a zone Z1 or for extracting a fluid F1 from zone Z1 in which said fluid circulates, whereby the rail comprises at least one orifice 3 that makes it possible for fluid F2 to pass into zone Z1 or for said fluid F1 to be extracted from zone Z1 and that in front of each orifice comprises at least one means 5 for at least partial blocking of the orifice, whereby the means is located downstream or upstream from the rail in the direction of circulation of fluid F2 and that makes it possible for fluid F2 to pass into zone Z1 or for said fluid F1 to be extracted from zone Z1. Use of the device for monitoring the injection or extraction of a first fluid in the simultaneous presence of a second fluid that is different from the first fluid.

Abstract: An access valve suitable for controlling fluid flow into and out of a chromatography column has a central axially movable probe with a head (71) acting as a spool valve in a barrel (6). Axial movement of the probe adjusts the valve between a fully open condition, in which both a first conduit (73) extending through the probe and a second conduit (51) defined around the probe are open to the column interior, a partly open condition in which a second sealing land (76) on the probe closes the second conduit (51), and a fully closed position in which both conduits are closed. The three positions are useful for packing and unpacking chromatography media into and from the column. In the closed condition of the valve, the first and second conduits (73, 51) communicate with one another so that the valve interior can be cleaned while the column is operating.

Abstract: A method and apparatus for high-throughput identity confirmation, quantitation and purity determination of a compound of interest in a mixture of compounds is disclosed. According to the method, a chemical mixture, such as may be obtained from a chemical library, is processed to obtain a stream having a time-varying composition, such as by using a high pressure liquid chromatograph. The stream is split into two portions or streams for substantially contemporaneous detection in a compound-identifying device, such as a mass spectrograph, and in a compound-quantitating device, such as an evaporative light scattering detector. A peak in a chromatogram obtained from the compound-quantitating device is identified as the compound of interest by cross-correlation, via elution time, with chromatographic results obtained from the compound-identifying device. Once the peak is identified as corresponding to the compound of interest, the corresponding peak area is used for quantitation and purity determination.

Abstract: The invention concerns an HPLC-based device and method for separating high complex substance mixtures. Plant and microbial extracts are high complex substance mixtures. They contain large amounts of extremely polar and non-polar materials. In principle, said mixtures can be separated by using a chromatic method. However, separation with existing chromatographic devices, for instance HPLC installations, is extremely time-consuming. The invention seeks to create a HPLC installation that separates fully automatically high complex substances in a very short time in such a way that said substances are broken down into their components in an almost pure state and can then be fed into a test system. To this end, said HPLC-based device comprises separation column units (A, F),fractionating column units (E, G), detector units (7, and 20, 21), pumping units (B, C, D) and fraction collecting units.

Abstract: Single pass methods and systems for measuring the total masses of individual compounds present in fluid samples in real time, and particularly for fluid samples prepared in microtiter plate format are provided. Individual compounds are isolated by fluid separation column (14). Portions of the individual compounds isolated by column (14) are analyzed by mass spectrometer (16), which determines their concentration on the basis of their molecular weights, and an evaporative light scattering detector (24), (which determines the total masses of each of the isolated compounds passing therethrough). Total collected masses of the individual compounds are calculated by determining the amount and portion of the isolated compounds diverted into evaporative light scattering detector (24) during a period of fraction collection.

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: An apparatus and process for regulating the flow rate of at least one fluid or effluent circulating in a simulated moving bed comprises a plurality of beds disposed in a closed loop in at least one chromatographic column (1) and comprising at least one means for recirculating fluid and comprising at least two lines for injecting fluid at a controlled flow rate and at least two lines for withdrawing fluid, one of said withdrawal (extract or raffinate) lines being under flow rate control, the other (60) being under pressure control via at least one control valve (6), and is characterized in that said pressure controlled withdrawal line (60) comprises, in addition to the control valve, comprises at least one restriction means (201) enabling the pressure downstream of at least one of the beds to be reduced. One embodiment of the use of the invention is for separating a xylene isomer.

Abstract: A preparative chromatographic cyclical process utilizing a single column comprising, at steady state: (a) establishing and maintaining a circulating chromatographic profile through said column and through one solvent pump; (b) discontinuously and periodically injecting a sample comprising at least two components, into the interior of said maintained circulating profile; and (c) collecting, discontinuously and periodically, at least two enriched fractions from said circulating profile.

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 kit for preparing an implantable graft, particularly an implantable, composite bone graft is provided. The kit includes a porous, biocompatible, sterile substrate and a container configured to retain the substrate and to permit flow of a cell suspension, particularly a bone marrow aspirate suspension therethrough. A method which employs such kit for preparing a composite implantable bone graft is also provided. The method includes the steps of providing a bone marrow aspirate suspension and passing the bone marrow aspirate suspension through a porous, biocompatible, implantable substrate to provide a composite bone graft having an enriched population of connective tissue progenitor cells. The composite bone graft prepared by the present method contains an enriched population of connective tissue progenitor cells and a greater number of connective tissue progenitor cells per unit volume than that found in the original bone marrow aspirate.

Abstract: This invention relates to a process for separating epsilon caprolactam from a feed mixture comprising epsilon caprolactam and octahydrophenazine which process comprises contacting under adsorption conditions said mixture with an adsorbent, selectively adsorbing said epsilon caprolactam to substantial exclusion of said octahydrophenazine, removing the non-adsorbed portion of the feed mixture from contact with the adsorbent, and thereafter recovering high purity epsilon caprolactam by desorption under desorption conditions. The process can also be conducted in a batch or semi-batch manner or in a continuous manner using moving bed or simulated moving bed technologies.

Abstract: This invention relates to a process for separating epsilon caprolactam from a feed mixture comprising epsilon caprolactam and one or more epsilon caprolactam isomers selected from the group consisting of 4-ethyl-2-pyrrolidinone, 5-methyl-2-piperdinone, 3-ethyl-2-pyrrolidinone and 3-methyl-2-piperdinone which process comprises contacting under adsorption conditions said mixture with an adsorbent, selectively adsorbing said epsilon caprolactam isomers to substantial exclusion of said epsilon caprolactam, removing the non-adsorbed portion of the feed mixture from contact with the adsorbent, and thereafter recovering high purity epsilon caprolactam. The epsilon caprolactam isomers can be recovered by desorption under desorption conditions. The process can be conducted in a batch or semi-batch manner or in a continuous manner using moving bed or simulated moving bed technologies.

Abstract: Disclosed is a single-phase fluid distributor-mixer-extractor for separating beds of granular solids used in chromatography. The distributor includes a device for adding or removing a secondary fluid. The distributor further includes at least one calibrated orifice having a geometry designed to create a sufficient pressure drop to confine fluid turbulence inside a mixing chamber.

Abstract: An apparatus and process are described for simulated moving bed separation in which line containing fluid containing the desired product is flushed at least once by a secondary fluid entering each distribution plate or by a fluid leaving each of said plates during at least a portion of a period of time between two successive permutations of the principal supply lines and the principal extraction lines, or during the entirety of said periods, the secondary fluid being selected from the group formed by the solvent, the fluid containing the desired product and the fluid containing the desired product freed of at least a portion of the solvent.

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: An apparatus for equalising pressure and flush in a vessel (1) has a chromatographic separation chamber (5), a distribution plate (3) or collection plate located in the vessel, a pressure equalisation chamber (4) defined at least in part by the extremity of the vessel and by a first face of the plate, the separation chamber (5) being defined by a second face of the distribution or collection plate, a first conduit (6) which places a first fluid in communication with the distribution or collection plate, the separation chamber (5) communicating with the equalisation chamber (4) via a flush chamber (10) comprising a first opening (21). A line (9) for supplying a second fluid which is substantially pure or substantially non contaminated is directly connected to the flush chamber at a point such that a portion of the second fluid can circulate towards the pressure equalisation chamber via a further opening (20) and the remaining portion can circulate towards the separation chamber via the first opening (21).

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 invention provides a system utilizing computer databases, high pressure liquid chromatography and mass spectrometry to isolate, purify and identify compounds present in a chemical library of reaction products, especially products of liquid phase (solution) chemical reaction, to produce a purified chemical library with each purified compound tracked to the reaction product from which it originated.

Abstract: The device comprises at least one column 1 that is filled with a number of beds A.sub.n having an adsorbent that are separated by a fluid distributor plate P.sub.i. Each plate is divided into a number of sectors P.sub.10 and P.sub.11, and each sector comprises at least one fluid distribution chamber 13 that is pierced with openings and a circulation space 8 in the vicinity of the openings. The chambers of the plate are connected to a line 10 for transfer to the outside. With respect to the chambers on a plate, transfer line 10 P.sub.i is connected to another transfer line 20 relative to chambers 23 on another plate (P.sub.i+1 or P.sub.i+2) that is arranged downstream by a bypass line L.sub.1,2. The latter comprises means 14, 15, 16 for monitoring and adjustment of the flow of fluid that circulates there, such that the distribution chambers are flushed by a fluid which has approximately the same composition as that of the fluid that circulates through circulation space 8 at each of the chambers.

Abstract: The invention is a column for separating a substance from a liquid having a plurality of separable compounds. The column has at least a first and a second bed of granular solids separated by at least one device, the device has at least a collection device which collects the substance to be separated, the collection device being in fluid connection to at least one mixing chamber, at least a first circuit for injection and/or removal of a first secondary fluid B.sub.1 and at least a second injection and/or removal circuit of a second secondary fluid B.sub.2. The injection and/or removal circuits are in communication with the mixing chamber with at least one opening allowing passage of the secondary fluids B.sub.1, B.sub.2 into the mixing chamber.

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: A method for separating acid and sugars obtained from liquids resulting from the acid hydrolysis of a material containing at least one of cellulose and hemicellulose is disclosed, comprising adding the liquids to a separation unit comprising a bed of anionic exchange or exclusion chromatographic material whereby the acid is adsorbed onto the chromatographic material, thereby producing a series of first fractions comprising sugar solutions and a later series of fractions comprising acid solutions. A process for an economical, energy efficient production of ethanol from municipal solid waste and other cellulosic feedstocks is also disclosed.

Abstract: A liquid chromatograph apparatus has a precolumn and an analyzing column which are connected through a 8-port-two-position-switching valve wherein the switching valve is capable of switching between two movable positions wherein a flow path for a solvent directing from the precolumn to the analyzing column is formed in one of the two movable positions; a flow path for the solvent directing from the analyzing column to the precolumn is formed in the other of the two movable positions, and the flow paths formed in the two movable positions are such that flowing directions of the solvent in the precolumn are opposite and flowing directions of the solvent in the analyzing column are the same.

Abstract: The present invention pertains to an apparatus for gathering analyte. The apparatus comprises a pumping mechanism for pumping solvent at supercritical pressure. The apparatus also comprises an extraction mechanism which receives a first sample and at least a second sample separate and distinct from the first sample and extract analyte from them essentially simultaneously. The extraction mechanism is connected to the pump mechanism to receive solvent at supercritical pressure for extracting the analyte from the samples. The apparatus additionally comprises a collection mechanism for collecting analyte from the solvent after the analyte has been extracted from the samples. The collection mechanism receives the supercritical solvent having the analyte extracted from the samples from the extraction mechanism. The present invention pertains to a method for extracting analyte. The method comprises the steps of pumping solvent at a supercritical pressure.

Abstract: A method and apparatus for high-throughput identity confirmation, quantitation and purity determination of a compound of interest in a mixture of compounds is disclosed. According to the method, a chemical mixture, such as may be obtained from a chemical library, is processed to obtain a stream having a time-varying composition, such as by using a high pressure liquid chromatograph. The stream is split into two portions or streams for substantially contemporaneous detection in a compound-identifying device, such as a mass spectrograph, and in a compound-quantitating device, such as an evaporative light scattering detector. A peak in a chromatogram obtained from the compound-quantitating device is identified as the compound of interest by cross-correlation, via elution time, with chromatographic results obtained from the compound-identifying device. Once the peak is identified as corresponding to the compound of interest, the corresponding peak area is used for quantitation and purity determination.

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: The chiral isomers of 3-hydroxytetrahyrofuran are separated by means of liquid chromatography using a stationary phase comprising a substituted polysaccharide carbamate. The separation may be performed using a simulated moving bed adsorbent system. Suitable mobile phase materials comprise a mixture of a light paraffin and a low molecular weight aliphatic alcohol such as a mixture of n-hexane and ethanol. Amylose is the preferred polysaccharide.

Abstract: An access valve suitable for controlling fluid flow into and out of a chromatography column has relatively movable valve elements preferably represented by a central axially movable probe with a head acting as a spool valve in a barrel. Axial movement of the probe adjusts the valve between a fully open condition, in which both a first conduit extending through the probe and a second conduit defined around the probe are open to the column interior, and a partly open condition in which a sealing component of the probe closes the second conduit. Also, further axial movement of the probe provides a fully closed position in which both conduits are closed. The partly open position is useful for packing chromatography media into its column while the third position is useful for unpacking the same. In the closed condition of the valve, the first and second conduits communicate with one another so that the valve interior can be cleaned while the column is operating.

Abstract: Method for controlling with precision a permanent in-line process for separating constituents of a mixture in a simulated moving bed separation system from concentration and flow rate measurements.The system comprises a set of columns forming a closed loop comprising several zones between fluid injection and draw-off points. Control of the process (linear or nonlinear) is performed from a knowledge model and from a certain number of operating variables at a plurality of measuring points along the loop (concentrations and flow rates for example) and characteristic measurements of the fluids injected and drawn off. Ratios respectively indicative of the ratio, in each of the different zones, between the fluid flow rates and the simulated adsorbent material flow rates, are determined from actual values of controlled variables depending on the measured operating variables (purity of the constituents, system yield, etc.).

Abstract: An apparatus for the recognition of exchangeable parts in an analytical measuring instrument or in an analytical measurement system with several analytical devices, which contain exchangeable parts has identification modules each attached to an exchangeable part, and transmit-receive devices which can receive information signals from an identification module and send information signals to an identification module, and a control device which evaluates the information from an identification module. The control device can cause a message to be displayed on a display device, if the information read out from an identification module does not fulfill certain conditions, for example with regard to the quality of the corresponding part.