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: 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: A process for producing purified L-ascorbic acid, which comprises subjecting an aqueous solution of crude L-ascorbic acid to column chromatography using a strongly acidic cation exchange resin; and a method of purifying L-ascorbic acid, which comprises subjecting an aqueous solution of crude L-ascorbic acid to column chromatography using a strongly acidic cation exchange resin.

Abstract: Improved liquid chromatography systems having components made of titanium, coated stainless steel, or organic polymeric material are useful in the separation of nucleic acid fragments, particularly large fragments of double-stranded nucleic acids, by ion pairing reverse phase chromatography. The titanium, coated stainless steel, or polymeric components 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 may be employed to remove multivalent ions from the system. The multivalent cation capture resin may be contained in a guard disk, a guard column, or a guard cartridge.

Abstract: In the simulated moving bed chromatographic separation process, preferably using a simulated moving bed chromatographic separation apparatus with rotary valves and/or check valves, a supercritical fluid is used as an eluent and thereby efficiency in separation and operation is remarkably improved and the concentration step after the chromatographic separation is not required.

Abstract: The present invention relates to a method for the processing of molecules by determining one or more selection parameters for a plurality of molecules; selecting a compatible grouping of molecules based on the selection parameters to form a set; forming a mixture of molecules of interest from the set; and resolving the mixture to fractionate the molecules of interest. The preferred method utilizes HPLC chromatography column to resolve and purify molecules which have different retention times.

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: A device for distributing, mixing, injecting, and/or removing several fluids, one of the fluids being a main fluid A.sub.1, and at least a first secondary fluid B.sub.1 and a second secondary fluid B.sub.2, said device having means (3, 4) for collecting said main fluid A.sub.1, said collecting means being related to at least one mixing chamber having at least one wall substantially parallel to the device axis circuit (12, 5) of a first secondary fluid B.sub.1, and at least a second injection and/or removal circuit (13, 6) of a second secondary fluid B.sub.2, said injection and/or removal circuits being in communication with the mixing chamber (7) by means of one or more openings (15, 16) allowing passage of said secondary fluids B.sub.1 and B.sub.

Abstract: The invention relates to a method for fractionating a solution by a chromatographic simulated moving bed method in which the liquid flow is effected in a system comprising at least two sectional beds in different ionic forms. The fractions enriched with different components are recovered during a multi-step sequence including the following operations, i.e., phases: feeding phase, eluting phase, and recycling phase. The liquid present in the sectional packing material beds with its dry solids concentration profile is recycled during the recycling phase in a loop comprising one, two, or more sectional packing material beds. The method can be employed for the following examples, fractionating sulphite cooking liquor, molasses, and vinasse.

Abstract: Methods and apparatus for extracting an analyte from a sample using a field-portable extraction instrument. The preferred embodiment of the extraction instrument includes an extraction fluid source, a sample container, a valve element, a nozzle, and a collection trap vessel. The methods of the present invention include the steps of inserting the sample into the sample container, attaching the sample container to the instrument, and providing a quantity of pressurized extraction fluid from the pressurized extraction fluid source into the sample container to initiate the extraction process. Extraction is facilitated by directing the extraction fluid into the sample at a rapid flow rate such that the sample and extraction fluid are vigorously mixed and a sample/solvent mixture is created. The valve element is then operated to isolate the extraction fluid source and to fully close the sample container.

Abstract: Various chemicals such as pharmaceuticals and petrochemicals are chromatographically separated in small quantities using an apparatus comprising a number of serially connected adsorbent-containing chambers. The chambers are linked together with valving necessary to simulate the continuous countercurrent flow of the adsorbent and liquid phases. The apparatus employs three three-port valves per chamber to direct liquid flow. Pressure pairing of the valves and the four major process streams protects product purity.

Abstract: A process for regulating at least one flow of at least one fluid or effluent circulating in a simulated moving bed comprising columns which form a closed loop containing at least one device such as a recycling pump introducing a pressure anisotropy. Every time an injection or extraction point passes from one part of the pump to the other, a control device which controls a fluid flow regulating means for the fluid under consideration, regulated about a set value, is caused to stop regulation temporarily, and substantially simultaneously the regulating means is placed in a position which allows it to approach the desired value, preferably to reach the desired flow rate and to begin to regulate the flow rate about the desired set value, to keep the flow rates in all the zones in a simulated moving bed constant. The process is especially applicable Application to the separation of para-xylene from a mixture of xylenes.

Abstract: The invention provides a multistage membrane system for the recovery of solvents and solutes from chromatographic systems, including first means for directing a first fluid stream of a main eluting fraction, containing target molecules to be concentrated and solvent, to a first filtration membrane unit for concentration and recovery of the target molecules at the feed side of the first membrane; second means for directing fluid streams of other eluting fractions of the chromatographic process, containing contaminants and solvent, to a second filtration membrane unit for concentration and collection of the contaminant solutes at the feed side of the second membrane unit; and third means for directing filtered solvent coming from the permeate side of the first filtration unit to the feed side of the second filtration membrane unit, whereby the filtered solvent intermixes with the fluid stream of other eluting fractions.

Abstract: An automated HPLC system separates, identifies, purifies, and quantitates complex mixtures of reaction products or natural products on a semi-preparative or preparative scale, thus enabling rapid compilation of combinatorial libraries with minimal operator involvement.

Abstract: A syringe pump particularly adapted for delivery of small volumes at a high pressure in an accurate and reproducible manner. The syringe pump includes a frame, a motor attached to the frame, and a lead screw drivably connected to the motor. A cover seal is mounted to the front end of the lead screw, the cover seal having grooves formed therein to facilitate mounting and demounting of the cover seal. The pump further includes a cylindrical barrel within which the cover seal reciprocates, the barrel being made of a ceramic material, wherein the barrel is fixedly attached to the frame at the front end and floatably mounted to the frame at the back end. A barrel head is mounted to the front end of the barrel for closing off that end of the barrel, the barrel head including an outlet port for allowing fluid to enter and exit the barrel. In addition, the present invention includes a multi-syringe gradient syringe pump, a liquid chromatography system, a cover seal, and a mixer for mixing multiple flow streams.

Abstract: Resolution of a mixture of organic materials by simulated moving bed chromatography using a weakly interacting adsorbent as a stationary phase can be routinely effected with a liquid mobile phase characterized by atypically low values of k' with recoveries of at least 95% and a purity of at least 95%. In particular, values in the range 0.1<k'<1.0 are recommended with a resulting savings in mobile phase consumption, inventory, and recovery.

Abstract: A method of recovering hydrogen peroxide from colored aqueous solutions is disclosed. The solution is brought in contact with a non-ionic size-exclusion chromatography resin made up of packed particles having narrow, low molecular weight pores. The higher molecular weight colored constituents are largely excluded from the pores causing these constituents to be more rapidly eluted with water along the exterior of the particles. Hydrogen peroxide molecules are small enough to enter the pores several times in their passage through the resin which slows their progress sufficiently to cause elution of hydrogen peroxide after the colored constituents have been eluted, effectively resolving the two components.

Abstract: The subject of the invention is a process for extracting pure lactic acid from fermentation liquors by ion exchange chromatography on a strongly acidic cation exchanger, preferably in H.sup.+ form. In a first step, the NH.sub.4 lactate coming from the fermentation is converted into the free acid by genuine ion exchange. This conversion is preferably effected on a weakly acidic cation exchanger in H.sup.+ form.

Abstract: The invention relates to a method for the fractionation of sulphite cooking liquor by a chromatographic simulated moving bed system in which the liquid flow is effected in a system comprising at least two chromatographic sectional packing material beds. In this method, at least one fraction enriched with monosaccharides and one fraction enriched with lignosulfonates are recovered during a multi-step sequence comprising the following phases: feeding phase of sulphite cooking liquor, eluting phase and recycling phase. The liquid present in the sectional packing material beds with its dry solids profile is recycled in the recycling phase in one or more loops comprising one or more sectional packing material beds.

Abstract: Various chemicals such as pharmaceuticals and petrochemicals are chromatographically separated in small quantities using an apparatus comprising a number of serially connected adsorbent-containing chambers. The chambers are linked together with valving necessary to simulate the continuous countercurrent flow of the adsorbent and liquid phases. The apparatus employs three three-port valves per chamber to direct liquid flow. Pressure pairing of the valves and the four major process streams protects product purity.

Abstract: A preparative chromatographic cyclical process comprising, at steady state: establishing a figure-of-eight circulating chromatographic profile between two chromatographic columns with the provision that said chromatographic profile never passes through a pump; discontinuously and periodically injecting a sample comprising at least two components, into said circulating profile; and collecting, discontinuously and periodically, at least two enriched fractions from said circulating profile, the apparatus for conducting this process comprising only two chromatographic columns, at least one solvent pump, an injection pump, two 4-way valves, and conduit communicating said columns and the two 4-way valves in the form of a figure-of-eight pattern without traversing a pump, and conduit communicating said at least one solvent pump and at least one of said columns.

Abstract: A process for effectively and economically separating an ionic component such as acid from a nonionic component such as sugar in polar solutions using ion exclusion technology whereby the viability of using hydrolysis to convert wood and agricultural waste products such as corn stover into fuel alcohol is substantially effective. Underlying the gist of this invention are newly discovered methods by which dispersion, caused by shrinkage of resin within ion exclusion columns, is controlled resulting in operation of such columns, over a wide range of process conditions to produce separate and distinct elution profiles for the acid and sugar. Successful operation of these new ion exclusion methods, techniques, and systems can replace lime precipitation which currently is being used in acid hydrolysis processing.

Abstract: Resolution of a mixture of organic materials by simulated moving bed chromatography using a weakly interacting adsorbent as a stationary phase can be routinely effected with a liquid mobile phase characterized by atypically low values of k' with recoveries of at least 95% and a purity of at least 95%. In particular, values in the range 0.1<k'<1.0 are recommended with a resulting savings in mobile phase consumption, inventory, and recovery.

Abstract: A variable-orifice fluid restrictor for use with a supercritical extractor or 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 is disposed toward the inlet line. The distal end of the probe includes an adjustable orifice means adapted for metering the fluid and having first and second orifice members and an adjusting stem having first and second ends. The adjustable orifice means is adjacent to the outer surface of the probe and the orifice means is adjustable with the adjusting stem. The end of the adjusting stem is located at the distal end of the probe and is adapted for moving the first orifice member with respect to the second orifice member to control the adjustable orifice for varying the restriction of fluid passing through the adjustable orifice.

Abstract: A system for pretreating sample streams including a concentrated matrix compound to neutralize the compound. The system includes an electrochemical membrane device in which sample flows through a sample flow channel of the device separated from a matrix ion receiving flow channel by an ion exchange membrane preferentially permeable to ions of the opposite charge to the ions to be analyzed. The ionic species in the thus-pretreated sample are directed to an analytical system such as an ion chromatograph.

Abstract: In a simulated mobile bed separation process, perturbations are corrected in the compositions of an extract (EA) or raffinate (RB) due to the dead volume introduced by at least one recycling pump (P) or compressor for a liquid, supercritical or gaseous mixture in a closed circuit of columns.

Abstract: In a simulated mobile bed separation process, perturbations are corrected in the compositions of an extract (EA) or raffinate (RB) due to the dead volume introduced by at least one recycling pump (P) or compressor for a liquid, supercritical or gaseous mixture in a closed circuit of column sections. The volume of the section immediately upstream of the dead volume is reduced by an appropriate value when said dead volume is located downstream of this section and upstream of the extraction streams of said section, or the volume of the section immediately downstream of the dead volume is reduced by an appropriate value when the dead volume is located downstream of the injection streams into said section and upstream of this section.The invention is applicable to the separation of isomers of aromatic hydrocarbons containing 8 carbon atoms.

Abstract: Perturbations are corrected in the compositions of an extract (EA) or raffinate (RB) due to the dead volume introduced by at least one recycling pump (P) for a liquid, supercritical or gaseous mixture in a closed circuit of column sections, or due to a degradation in their separating power each time an injection or extraction stream passes from a position anterior to a position posterior to each of the dead volumes in the circuit or each section whose separation power has been degraded. Firstly, the connection period for said stream to the circuit is increased by an appropriate value, and then when the stream passes from the posterior position to the dead volume, or connection to the degraded section, to the following position, the connection period is reduced so that the period regains the value which would have been applied if each of the dead volumes had been ignored or the degradation in the separation powers had been ignored.

Abstract: A method and apparatus using suppression of eluents for the analysis of anions or cations in ion chromatography. The invention relates to the intermittent use of the electric field during electrochemical suppression to minimize background noise during detection of the ionic species caused by the application of an electric field using an electrolytic membrane suppressor. Using this intermittent electrochemical suppression system allows the detection of the analyte in the absence of the electric field. The system finds particular benefit in reducing background noise created during electrochemical suppression, and in reducing the baseline interference when analyzing organic solvent-containing samples.

Abstract: Various chemicals such as pharmaceuticals and petrochemicals are chromatographically separated in pilot plant quantities using an apparatus comprising a number of chambers containing an adsorbent linked together with valving necessary to simulate the continuous countercurrent flow of the adsorbent and liquid phases. The apparatus preferably comprises five multiport rotary valves, each having at least one port for each column. The fifth rotary valve provides a serial interconnection between the columns and also ensures the desired unidirectional flow of fluid in the apparatus.

Abstract: The method of chromatographic separation comprises: a feed-withdrawal step in which, with liquid flow being permitted from the first to the third unit beds in the simulated moving bed, an eluant is fed into the first unit bed and the feed stock is fed into the third unit bed while, at the same time, part of the effluent from the first unit bed is withdrawn from the system as a fraction rich in component B and the effluent from the third unit bed is withdrawn from the system as a fraction rich in component C; a circulation stage in which, with liquid circulation being permitted through the simulated moving bed, the liquid in the simulated moving bed is moved downstream without liquid feed to or withdrawal from the simulated moving bed; and a withdrawal stage in which, with liquid flow being permitted from the second to the first unit beds, the eluant is fed to the second unit bed and the effluent from the first unit bed is withdrawn from the system as a fraction rich in component A; wherein, after the above th

Abstract: A process for effectively and economically separating an ionic component such as acid from a nonionic component such as sugar in polar solutions using ion exclusion technology whereby the viability of using hydrolysis to convert wood and agricultural waste products such as corn stover into fuel alcohol is substantially effective. Underlying the gist of this invention are newly discovered methods by which dispersion, caused by shrinkage of resin within ion exclusion columns, is controlled resulting in operation of such columns, over a wide range of process conditions to produce separate and distinct elution profiles for the acid and sugar. Successful operation of these new ion exclusion methods, techniques, and systems can replace lime precipitation which currently is being used in acid hydrolysis processing.

Abstract: Disclosed is a process for producing high-purity glucose by saccharifying liquefied starch with the aid of an enzyme, in which the saccharification reaction of the liquefied starch is discontinued at a point where the glucose content is less than 96% by weight, preferably within the range of 80 to 93% by weight, on a solid basis. The resulting saccharified solution is filtered, concentrated and softened as required, and then fractionated by subjecting it to column chromatography. Thereafter, the resulting glucose fraction is recovered. This process makes it possible to produce high-purity glucose efficiently in spite of a reduction in saccharification time.

Abstract: A system for pretreating sample streams including a concentrated matrix compound to neutralize the compound. The system includes an electrochemical membrane device in which sample flows through a sample flow channel of the device separated from a matrix ion receiving flow channel by an ion exchange membrane preferentially permeable to ions of the opposite charge to the ions to be analyzed. The ionic species in the thus-pretreated sample are directed to an analytical system such as an ion chromatograph.

Abstract: Resolution of a racemic mixture of organic materials by simulated moving bed chromatography using a chiral stationary phase can be routinely effected at atypically low values of k' with recoveries of at least 95% and an optical purity of at least 95%. In particular, values in the range 0.1<k'<1.0 are recommended with a resulting savings in mobile phase consumption, inventory, and recovery.

Abstract: A process for recovering and reusing a solvent and optical isomers, characterized by using a simulated moving packed bed which comprises an inlet for an eluent, an outlet for an extract containing an optical isomer strongly adsorbable on the packing, an inlet for a liquid containing an optical isomer mixture and an outlet for a raffinate containing an optical isomer weakly adsorbable on the packing in this order in a packed bed containing packings for optical resolution and arranged in a solvent circulation passage, and in which the inlets and the outlets are intermittently and successively moved in the direction of liquid flow in the packed bed: recovering the solvent and the optical isomer(s) from The resultant extract and/or raffinate; returning the recovered solvent into the solvent circulation passage; or when the solvent is not recovered, heating the extract or raffinate to racemize an undesired optical isomer and reusing the resultant solution containing a racemic modification for the separation of the

Abstract: A method and device for detecting the presence of a suspected antigen in a sample whereby the antigen is trapped using affinity chromatography and the remaining eluant is differentially analyzed against a parallel processed control. The sample is first chromatographically segregated into distinct zones and the resulting eluant is split into two streams. One stream is contacted with a solid phase having immobilized capture ligands specific to the antigen of interest. The other stream is passed through a similar solid phase where the capture ligands have been omitted. The two streams are then differentially analyzed, for example, with ultraviolet light absorption.

Abstract: When a strong base anion exchange resin, such as a chloride-form strong base anion exchange resin, is conditioned with a low concentration of hydroxyl (for example, an NaOH solution with a concentration between 1 and 10 mM), the conditioned resin separates in, sit, Is from sugars and sugar alcohols, while still allowing ready desorption of the sugars from the resin. The feedstock is first passed over a column containing this conditioned resin, followed by a mobile phase solvent, preferably water. The inositols have a lower affinity for the treated resin than do the sugars and sugar alcohols in the feedstock, and therefore pass through the column more quickly. The process may economically be performed on industrial-scale inositol separations, particularly when used in a preferred simulated moving bed chromatographic system.

Abstract: Various chemicals such as pharmaceuticals and petrochemicals are chromatographically separated in pilot plant quantities using an apparatus comprising a number of chambers containing an adsorbent linked together with valving necessary to simulate the continuous countercurrent flow of the adsorbent and liquid phases. The apparatus preferably comprises five multiport rotary valves, each having at least one port for each column. The fifth rotary valve provides a serial interconnection between the columns and also ensures the desired unidirectional flow of fluid in the apparatus.

Abstract: A method and apparatus for the partial or complete continuous separation of isotopes of gadolinium, especially high thermal neutron capture cross-section gadolinium isotopes, using continuous, steady-state, chromatography in which an ion exchange resin is the stationary phase, an aqueous solution of ions based on a mixture of gadolinium isotopes is the feed phase, and an aqueous acid eluant solution is the mobile phase. The method involves the mobile phase eluting or desorbing the gadolinium isotopic solute or ligand adsorbed on the stationary phase under conditions such that each of the various naturally occurring isotopes of gadolinium is primarily eluted in an elution volume distinct from the elution volumes of the other isotopes. In a preferred embodiment, the conditions are such that at least one of the elution volumes contains essentially only one isotope of gadolinium.

Abstract: A method is provided for removing iodide from aqueous solutions in which the iodide is converted to iodine. The porous granules of the polyvalent metal chelating resin containing zirconium peroxide bound to the chelating groups thereof is contacted with the aqueous iodide solution. The iodine is formed within the granules and retained therein, permitting the aqueous solution to be separated to create iodine. This iodine can be recovered by organic solvent elution. The oxidative capacity of the resin granules has been reduced, it can be regenerated after removal of the obtained iodine by contacting the resin granules with aqueous hydrogen peroxide.

Abstract: A high pressure liquid chromatography injection system with two independently controlled valves and a pump is provided which permits the simultaneous and independent concentration and analysis of trace components using two different solvent systems.

Abstract: The present invention is a collection system for use with supercritical fluid extraction. The system comprises a device for collecting analyte from a fluid having the same. There is also a restrictor for controlling flow of analyte to the collecting device. The restrictor converts the fluid with analyte from a first pressure to a second pressure. The second pressure is less than the first pressure. The first pressure is a supercritical pressure. The restrictor is in fluidic communication with the collecting device. There is also a device for deabsorbing the analyte from the collecting device. The deabsorbing device is in fluidic communication with the collecting device. The collection system also includes a chromatograph for analyzing the analyte. The chromatograph is in fluidic communication with the collecting device to receive deabsorbed analyte. The chromatograph is remote from the collecting device. The chromatograph can be either a gas chromatograph or a liquid chromatograph.

Abstract: This invention relates to a process of and apparatus for the continuous and selective separation of boron-10 (B.sup.10) isotope having high neutron capture cross-section from boron-11 (B.sup.10) isotope from a mixture of boron isotopes in a boric acid solution by using a weak base ion exchange resin and water eluant in a continuous annular chromatograph.

Abstract: A process for the partial or complete simultaneous separation of isotopes of erbium, especially high thermal neutron capture cross-section erbium isotopes, using continuous, steady-state, chromatography in which an ion exchange resin is the stationary phase, an aqueous solution of ions based on a mixture of erbium isotopes is the feed phase, and an aqueous acid eluant solution is the mobile phase. The process involves the mobile phase eluting or desorbing the erbium isotopic solute adsorbed on the stationary phase under conditions such that each of the various naturally occurring isotopes of erbium is primarily eluted in an elution volume distinct from the elution volumes of the other isotopes. In a preferred embodiment, the conditions are such that at least one of the elution volumes contains essentially only one isotope of erbium. The process is preferably conducted in a continuous, steady-state manner, and in particular is preferably conducted in a continuous annular chromatograph (CAC).

Abstract: A process for recovering and reusing a solvent and optical isomers, characterized by using a simulated moving packed bed which comprises an inlet for an eluent, an outlet for an extract containing an optical isomer strongly adsorbable on the packing, an inlet for a liquid containing an optical isomer mixture and an outlet for a raffinate containing an optical isomer weakly adsorbable on the packing in this order in a packed bed column containing packings for optical resolution and arranged in a solvent circulation passage, and in which the inlets and the outlets are intermittently and successively moved in the direction of liquid flow in the packed bed; recovering the solvent and the optical isomer(s) from the resultant extract and/or raffinate; returning the recovered solvent into the solvent circulation passage; or when the solvent is not recovered, heating the extract or raffinate to racemize an undesired optical isomer and reusing the resultant solution containing a racemic modification for the separation

Abstract: A process for recovering and reusing a solvent and optical isomers characterized by using a simulated moving packed bed which comprises an inlet for an eluent, an outlet for an extract containing an optical isomer strongly adsorbable on the packing, an inlet for a liquid containing an optical isomer mixture and an outlet for a raffinate containing an optical isomer weakly adsorbable on the packing in this order in a packed bed column containing packings for optical resolution and arranged in a solvent circulation passage, and in which the inlets and the outlets are intermittently and successively moved in the direction of liquid flow in the packed bed; recovering the solvent and the optical isomer(s) from the resultant extract and/or raffinate; returning the recovered solvent into the solvent circulation passage; or when the solvent is not recovered, heating the extract or raffinate to racemize an undesired optical isomer and reusing the resultant solution containing a racemic modification for the separation

Abstract: A description is given of a process for the separation of at least one constituent from a mixture containing at least two polyglycerols having consecutive degrees of polymerization from 2 to 10, in which said mixture is passed into at least one column lined with an adsorbent particular phase through which flows a liquid eluent, said phase consisting of a cationic organic resin such as a styrene-divinyl benzene copolymer or an anionic resin, or a mineral phase chosen from among silicas, aluminas and zeolites in normal form or modified by grafting, said liquid eluent consisting of an aqueous phase to which is optionally added a strong acid. The process described can be performed continuously or batchwise and in simulated counter-current (SCC) or simulated cocurrent manner.

Abstract: A separation process is described for separating a known material from a mixture of materials (which may contain unknown materials) using displacement chromatography. The process comprises passing a mixture of materials, including a known material to be recovered, dissolved in a liquid carrier, if necessary, through a first packed column and into a second packed column until all of the known material has passed through the first column and has been loaded onto the stationary phase packing in the second column. A displacement agent, capable of being more strongly bound on the stationary phase packing in the second column than the known material, is then passed through the second column to displace from that column all of the materials in the mixture less strongly bound than the known material, and then to displace the known material from the second column.

Abstract: A process for separating optical isomers in a simulated moving bed system, which comprises introducing a solution containing an optical isomer mixture and a desorbing liquid into a packed bed containing an optical resolution packing therein and having front and rear ends thereof connected to each other endlessly via a fluid passage to circulate a fluid unidirectionally and at the same time drawing out a solution containing one of the separated isomers and another solution containing the other isomer from the packed bed, wherein a port 13 for introducing a desorbing liquid, a port 14 for drawing out a solution containing a strongly adsorbable optical isomer, i.e. an extract, a port 15 for introducing a solution containing a mixture of optical isomers, and a port 16 for drawing out a solution containing a weakly adsorbable optical isomer, i.e.