Abstract: A chromatography column includes a tubular member with an inlet end and a slidable porous member that bounds a chromatography media. The porous member is spaced sufficiently from the inlet end to define a receiving region.

Abstract: Energy efficiency of a thermal zone in an analytical instrument is improved by use of an oven housing module having an enclosure body defining an oven cavity, wherein the enclosure body exhibits a size and shape sufficient to receive a component to be subjected to temperature control within a thermal zone located in the oven cavity. A temperature control assembly includes a vent assembly communicating with ambient air, a fan, and a fast cooling flap, wherein the temperature of the thermal zone may be modulated by supplementing the oven cavity air with ambient air. The fast cooling flap may be operated for opening one side of the oven cavity to ambient conditions such that ambient air may be rapidly introduced to the oven cavity and the cavity air may be rapidly exhausted from the oven cavity for rapid cooling of the thermal zone.

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: The present invention relates to capillary columns including a monolith and a method for preparing a capillary column including a monolith. The monolith can be prepared by a sol gel method, and in the transformation from hydrosol to hydrogel, the monolith undergoes essentially no syneresis or volume shrinkage. Thus, deleterious effects of syneresis are avoided, such as the formation of channels having large dimensions that provide a pathway of least resistance for a mobile phase to effectively bypass portions of a stationary phase. The method for preparing a column having a monolith that undergoes essentially no syneresis involves a hydrogel solution that has a relatively low concentration of SiO2, i.e. less than about 5 g/100 mL.

Abstract: An electrically insulated gas chromatograph assembly suitable for high temperature operation in a miniaturized, low power, low thermal mass gas chromatograph instrument is provided. The gas chromatograph (GC) assembly includes a metal capillary GC column (152) having a ceramic fiber insulating layer (156) wrapped about an outer surface thereof. Heater wire (160) is similarly wrapped with a ceramic fiber electrical insulating layer (158). Resistive temperature device (RTD) wire (154) is positioned contiguous an outer surface of insulating layer (156). The composite assembly including insulated capillary GC column (152), insulated heater wire (160), and RTD wire (154), are bound together by applying thereto a spiral wrapped ceramic fiber insulating layer (162).

Abstract: A multichannel capillary column having an interior wall defining a single internal bore, wherein the interior wall defines a plurality of n channels and n ridges, wherein adjacent channels are partially separated by a respectively interposed ridge, and wherein a central, coaxial portion of the internal bore allows cross-channel fluid communication between all of the n channels.

Abstract: The invention relates to a device or equipment as well as to a method for the simultaneous, fractionating operation of a plurality of parallel chromatographic columns. It is particularly advantageous to apply this equipment and method in research, in the framework of organic synthesis for simultaneous, parallel separation, isolation and purification of a plurality of chemical compounds, e.g. of potential new active ingredients for medicaments, particularly also on the semi-preparative scale.

Abstract: Method for loading a column with a packing material by inserting one end of a column to be packed into a slurry of a packing material in a volatile solvent, allowing said slurry to be drawn into said end of said column by capillary action, withdrawing said end from said slurry, and removing said volatile solvent from the slurry that has been drawn into said end of said column, through the same end of the column at which the slurry entered, and sinteriing.

Abstract: A multi-passage capillary arrangement can be formed from ductile glass material into an assembly that has an essentially round outer cross section and multiple capillary passages with diameters of 250 micrometers or less. The multiple capillary assembly provides multiple capillary sized passages of a regularly recurring shape in a single cohesive bundle. The round outer cross section facilitates the use of the multiple capillary by providing a suitable surface for connections. The multiple capillary arrangement can be made by a method that provides uniform or nearly uniform capillary passages throughout the arrangement. The capillaries are useful for chromatograph applications and as flow restrictors.

Abstract: A chemical preconcentrator is disclosed with applications to chemical sensing and analysis. The preconcentrator can be formed by depositing a resistive heating element (e.g. platinum) over a membrane (e.g. silicon nitride) suspended above a substrate. A coating of a sorptive material (e.g. a microporous hydrophobic sol-gel coating or a polymer coating) is formed on the suspended membrane proximate to the heating element to selective sorb one or more chemical species of interest over a time period, thereby concentrating the chemical species in the sorptive material. Upon heating the sorptive material with the resistive heating element, the sorbed chemical species are released for detection and analysis in a relatively high concentration and over a relatively short time period. The sorptive material can be made to selectively sorb particular chemical species of interest while not substantially sorbing other chemical species not of interest.

Abstract: Apparatus and method for periodic analysis of trace amounts of volatile organic compounds in a waste gas provide for feeding of a sample of a waste gas first to an organics concentrator which isolates the volatile organic compounds from the waste gas sample and prepares a concentrated sample for feed to a gas chromatograph. In normal operation, a waste gas is continuously sampled from the waste gas source to produce a continuous waste gas flow through a switching valve and out a vent. A portion of that waste gas flow is periodically diverted by the switching valve and routed to the organics concentrator. The switching valve also receives calibration samples containing known concentrations of the volatile organic compounds prepared in a gas blender. It periodically feeds the calibration samples to the organics concentrator and the gas chromatograph for calibration of the system.

Abstract: A solute and a solvent with close boiling points or close polarities are separated and concentrated by vaporizing at least one of the solvent and solute, and selectively adsorbing the vaporized component in an apparatus having a vessel, and an absorbent with an opening into the vessel.

Abstract: A mixture of chromatographic particles and a solution of water, alcohol and metal alkoxide may be injected by means of a syringe into a capillary column as a gel. The volatile components in the gel are evaporated by means of heating and gas pressure reduction to form a porous sol-gel glass matrix attached to the inner wall of the separation channel. The pores are large enough for the passage of protons, neutral and ionic species but are too small to permit significant leaching of the chromatographic particles. The separation column so formed requires no frits to maintain the glass matrix in place in the column. Electrical potential difference and/or pressure difference may be applied to cause fluid flow in the separation column to cause electrophoretic and chromatographic separation.

Abstract: An apparatus and method for sealing cartridges used in liquid chromatography. Such cartridges are commonly filled with media beds that are bounded axially by porous plates. The invention involves one or two sealing heads. Each sealing head comprises two slidably connected head pieces and an elastomeric sealing member. The head pieces and the elastomeric sealing member are sized to slide easily into an open end of a cartridge when the elastomeric sealing member is uncompressed. After insertion, relative movement of the head pieces compresses the elastomeric sealing member and causes the elastomeric sealing member to expand laterally so that it forms a seal against the cartridge, when the sealing head is pressed against the media bed or porous plate. An alternate sealing head comprises a plurality of head pieces and a plurality of annular elastomeric sealing members. One of the head pieces contains a body portion on which the other head pieces and the sealing members are slidably mounted.

Abstract: The invention provides methods and systems for identifying compounds released from a semi-conductor wafer. Compounds are released from the wafer by subjecting the wafer to a rapid temperature excursion in a very low pressure chamber. The released compounds are often isolated using gas chromatography. Diffusion between the layers of a multiple layer semi-conductor structure can be minimized by directly heating a target surface of the wafer using radiant heating.

Abstract: An airflow director constructed for use with a separation column in a temperature-controlled air bath in a chromatographic oven cavity, wherein the airflow director includes at least a first baffle locatable with respect to the separation column and to the low pressure and high-pressure regions of the air bath, wherein the baffle is configured to direct air flow away from the high-pressure region before passing over the separation column. The temperature-controlled air thereby mixes with oven cavity air before passing over the separation column, which is thereby less subject to thermal gradients.

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: A liquid chromatography apparatus with stationary and mobile phase temperature controls suitable for polynucleotide separations by MIPC and DMIPC processes. The apparatus includes heater means with a temperature control system; a matched ion polynucleotide chromatography separation column having an inlet end; a coil of capillary tubing having an inlet end and an outlet end. The outlet end of the capillary tubing is connected with the inlet end of the separation column. The inlet end of the capillary tubing comprising means for receiving process liquid, the tubing having a length of from 6 to 400 cm having a linear tubing length of heating means. The separation column and the coil of capillary tubing are enclosed in the heater means. The capillary tubing preferably is PEEK or titanium. The heater means can be an air batch oven. Preferably, it is a heat-conducting block having a first heat transfer surface, a separation column receptacle, and a capillary coil receptacle.

Abstract: An apparatus and method for sealing a plurality of columns containing media for use in liquid chromatography. The invention involves two sealing assemblies, each having a plurality of sealing heads. The sealing heads are sized to receive ends of the columns and to seal the columns when the heads are compressed. Compressive force is exerted by or through springs to permit the sealing heads to adapt to the length of the media bed within each column. The apparatus may include a pressure containment vessel for subjecting the columns to radial compression.

Abstract: A device for establishing a flange connection, having a bearing which can act on a first flange, a counter-bearing which can act on a second flange, and a connecting lever between the two bearings is described. The invention is distinguished by the fact that the connecting lever is a lever with a drawing element. The drawing element and the lever each have a first and second end. The drawing element's first end engages the bearing and its second end jointedly mounts in between the first and second ends of the lever. The counter-bearing has at least one contact location for the first end of the lever and a recess for the drawing element.

Abstract: An apparatus and method for sealing cartridges used in liquid chromatography. Such cartridges are commonly filled with media beds that are bounded axially by porous plates. The invention involves one or two sealing heads. Each sealing head comprises two slidably connected head pieces and an elastomeric sealing member. The head pieces and the elastomeric sealing member are sized to slide easily into an open end of a cartridge when the elastomeric sealing member is uncompressed. After insertion, relative movement of the head pieces compresses the elastomeric sealing member and causes the elastomeric sealing member to expand laterally so that it forms a seal against the cartridge, when the sealing head is pressed against the media bed or porous plate.

Abstract: A tubular insert with a small internal volume is disposed inside the vaporization chamber at the inlet of a capillary column of a gas chromatograph such that the sample with a solvent injected into the vaporization chamber is carried by a carrier gas through the insert into the column. The internal volume of the insert is such that the retention time of the carrier gas through the insert is less than 4 seconds. A heater is controlled to maintain the temperature inside the vaporization chamber within a specified range above the boiling point of the solvent as the sample is injected into the vaporization chamber, and this temperature is subsequently raised to a final temperature above the boiling points of the components to be analyzed. The carrier gas pressure is temporarily increased for better efficiency as the sample is injected.

Abstract: The invention relates to a cartridge heater for a gas chromatography transfer device for substances which are to be analyzed, having a metal tube for accommodating a tube section to be heated and a heating coil arranged outside the metal tube, the metal tube bearing, on the outside, a groove which corresponds to the shape of the heating coil and in which a heating conductor is embedded in an electrically insulated manner with respect to the metal tube.

Abstract: SF.sub.6 gas is collected from the inside of a gas insulated machine during maintenance and inspection and is refined. Compositions of the refined SF.sub.6 gas are analyzed and confirmed to be reusable at the site. In the process of SF.sub.6 gas collecting and refining, acidic gases are neutralized and removed by a dry method using filters and the refined SF.sub.6 gas is collected in a collecting tank. In particular, after the refining, the composition of the collected SF.sub.6 gas is measured and confirmed by analysis equipment to quantitatively confirm whether or not the refined SF.sub.6 gas is reusable.

Abstract: Method for loading a column with a packing material by inserting one end of a column to be packed into a slurry of a packing material in a volatile solvent, allowing said slurry to be drawn into said end of said column by capillary action, withdrawing said end from said slurry, and removing said volatile solvent from the slurry that has been drawn into said end of said column, through the same end of the column at which the slurry entered, and sinteriing.

Abstract: Cartridges for high performance liquid chromatography are designed for use with a large number of repeated injections without excessive buildup of back pressure by the inclusion of a filter medium consisting of sintered stainless steel fibers formed into a non-woven structure whose pore size decreases in the direction of flow down to a pore size of less than ten microns.

Abstract: Relating to chromatographic processes and ion-exchange and affinity matrices, a spatial installation method for a bifunctional reagent that crosslinks and/or activates a polymer matrix is disclosed, with inside-outside installation of a bifunctional reagent on and within a polymer matrix. The polymer matrix is cellulose, agarose, or chitosan particles. The installation may be followed by inside-outside ligand attachment, by further reacting the matrix with a ligand or ionic group so that a higher concentration of ligand or ionic moiety occurs on the intra-particle volume than the outer matrix surface.

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: A sample inlet liner includes an internal surface barrier wherein the surface barrier is situated so as to circumvent undesirable reactions between the sample and the liner. The barrier surface composition includes PTFE to an extent sufficient to reduce or eliminate such undesirable reactions, and the surface barrier is situated so as to receive substantially all of the wetting of the liner by an injected sample, such that little or no contact is made by the sample with a surface that lacks sufficient PTFE. As a result, decomposition or adsorption of the sample is reduced.

Abstract: A gas chromatograph includes a carrier gas supply flow path to which a pressure sensor, resistance tube, and control valve are sequentially connected. A differential pressure sensor is situated on both sides of the resistance tube to measure the differential pressure. The control valve is controlled by a controlling portion through signals from the pressure sensor and differential pressure sensor to control a flow rate of a carrier gas. Thus, in the gas chromatograph, the flow rate of the carrier gas can be controlled without an expensive pressure regulator, and a pressure of the carrier gas to be supplied can be selected as desired.

Abstract: A precolumn separator provides a method of separating a solvent from a sample for use in a gas chromatograph. The precolumn has an independent carrier gas control mechanism which allows the carrier gas to be passed through the preseparation column at a rate favorable for stripping the solvent from the sample. The solvent-laden carrier gas is then purged through a purge vent which is separate from the gas chromatograph. After a period of time which effectively permits the carrier gas to be significantly removed from the sample, the flow rate of the carrier gas is reduced to the normal operating gas flow rate and the purge vent is closed. The sample is then passed through the column to the gas chromatographic column. A second purge vent can then be directed to the purge vent inlet in the gas chromatograph. Preferably, the preseparation column is a packed column which includes a separate heating element. The heating element, in turn, can be surrounded by an air cooled jacket.

Abstract: A protected fused-silica capillary liquid chromatography (liquid chromatography) column is shielded inside a single flexible tubing, which has the same length as the capillary and is integrated with the capillary in the packing process. The column has the advantages of a fused-silica capillary liquid chromatography column combined with the benefits of the shield tubing which makes the column more accurate, durable, and convenient to use, and less expensive to produce.

Abstract: An ion chromatography system analyzes the environment in semiconductor equipment for foreign materials. The system includes an impinger section for preparing a sample of the atmosphere, and an ion chromatography section. The impinger section includes an absorbent solution vessel, suction and exhaust piping connecting the vessel to the environment, and a pump for transporting atmosphere under pressure. The ion chromatography section includes a guard column, a separation column, and a detector. The suction pipe has an intake port positioned at a target site whose environment is to be analyzed. The impinger section is connected to the ion chromatography section so that the absorbent solution of the vessel directly enters the ion chromatography section. To promote the absorption of the atmosphere into the solution, the absorbent solution vessel may be in the form of an elongate diffusion scrubber having an outer cylindrical vessel and an inner tube made of a selective membrane.

Abstract: A column for capillary chromatographic separations, for example high performance liquid chromatography, capillary electrochromatography, or supercritical chromatography, includes a column bed of packing material arranged in the inner bore of the column, and a retainer for retaining the column bed in the interior of the column, wherein the retainer includes regions in the interior of the column having radial dimensions which are different from that of the inner bore. Preferably, the column is a fused silica capillary whose protective layer is removed in a detection area so that sample substances separated in the column can be detected by means of a light source which transmits radiation through the column which is detected by a detector.

Abstract: The present invention relates to liquid crystalline alkenes and liquid crystalline polysiloxanes prepared from these alkenes. More precisely, the present invention is related to the development of fused ring aromatic-containing side chain liquid crystal polysiloxanes (SCLCP). These liquids crystalline polysiloxanes are particularly useful as the stationary phase in column chromatography for the separation of various isomeric compounds, including polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated diberizofurans (PCDF), polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and polysubstituted benzenes.

Abstract: A new type of guard cartridge has been provided to prevent contamination of liquid chromatography (LC) columns by particulate and soluble contaminants. The cartridge is prepared by packing an empty tube with a chromatographic stationary phase and the packed tube is then sealed on both ends with porus sheets held in place by two collars. The cartridge gives minimum disturbance on column performance and significantly decreases the cost of production.

Abstract: A continuous emission monitoring system is disclosed for detecting toxic substances of various types in either stack gas or ambient air. Particular systems are illustrated for monitoring lewisite and chromium(VI). Each system employs a gas sampler that utilizes a high-volume, wet cyclone concentrator unit which scrubs the contaminants from the gas into water or another suitable scrubbing solution. In-line chemical processing of the contaminated sample thus obtained is accomplished either within the sampling unit or by an external chemistry processing module. After processing to provide an analyte in the sample indicative of the presence of a predetermined contaminant, the sample stream is delivered to an ion chromatograph or other analyzer to determine the presence and quantity of the analyte and indicate whether a danger level has been reached. This provides monitoring on an essentially real-time or near real-time basis.

Abstract: A closing element intended for closing off an end of a capillary gas chromatography column comprises a closing body provided with a blind hole, which tapers over at least a portion of the length thereof, and the walls of the tapering portion of the hole include an angle with the centerline of the hole, this angle being so small that upon placement of the closing element on the end of the capillary gas chromatography column, a self-locking engagement between the end of the column and the closing element occurs. The closing element is manufactured from a form-retaining, inert, gastight material.

Abstract: A gas chromatography oven is endowed with a shutter for the influx of air from the outside and a pair of shutters for the controlled outflow of air from the oven, the shutters being positioned on the rear wall of the oven, near the corners of the rear wall. On the upper wall of the oven, at least one injector of the sample to be analyzed and at least one detector are lodged in a removable drawer.

Abstract: A precolumn separator provides a method of separating a solvent from a sample for use in a gas chromatograph. The precolumn has an independent carrier gas control mechanism which allows the carrier gas to be passed through the preseparation column at a rate favorable for stripping the solvent from the sample. The solvent-laden carrier gas is then purged through a purge vent which is separate from the gas chromatograph. After a period of time which effectively permits the carrier gas to be significantly removed from the sample, the flow rate of the carrier gas is reduced to the normal operating gas flow rate and the purge vent is closed. The sample is then passed through the column to the gas chromatographic column. A second purge vent can then be directed to the purge vent inlet in the gas chromatograph. Preferably, the preseparation column is a packed column which includes a separate heating element. The heating element, in turn, can be surrounded by an air cooled jacket.

Abstract: A process for determining the amount of argon contamination present in high purity oxygen employing a combination apparatus including a gas chromatography apparatus, a pressure swing adsorption apparatus, and a conduit connecting the two apparatus to each other. The gas chromatography apparatus can be run with its column at about 70.degree. F. (21.1.degree. C.) or higher. A sample of the high purity oxygen is fed to the pressure swing adsorption apparatus, where a portion of the oxygen is removed, and then the thus modified sample is fed through the conduit to the gas chromatography apparatus. Since some of the oxygen has been removed with the pressure swing adsorption apparatus, the graph generated by the gas chromatography apparatus shows 2 resolved peaks, namely a small argon peak preceding a large oxygen peak, even though the column of the gas chromatography apparatus is not being cooled to cryogenic temperatures with a cryogen.

Abstract: A chromatography oven is described to achieve faster cool-down rates and to preferably lower the temperature difference that can be maintained between the oven temperature and ambient temperature. The oven includes a suitable housing having front and rear walls and four side walls, a fan within the housing adjacent to the rear walls, an ambient air intake vent means in the rear wall, and an exhaust vent means within a rear corner of one of the side walls adjacent to the rear wall for exhausting the tangential flow of air created by the rotating fan.

Abstract: An Analytical Glove Box System has a sealed instrumentation enclosure, a ve box having an injection port coupled to the instrumentation and an air lock through which sample vials can be passed from outside into the glove box. A pump is provided for withdrawing gas from the glove box enclosure through a filter system so that the glove box is maintained at a negative pressure with respect to ambient. Toxic chemical samples can thus be safely handled by an operator and analyzed with sophisticated instrumentation without the risk of contamination. All effluent from the glove box is filtered before release to ambient, leakage from the glove box is further eliminated due to the negative pressure differential maintained, and the instruments are isolated from the potentially contaminated environment of the glove box. The system further provides the ability to conduct highly toxic chemical analysis in field locations since it is portable (including air transportable) and is easily decontaminated.

Abstract: In a method of filling a liquid chromatographic column with particulate separation medium, a liquid suspension of the particulate separation medium is introduced into one end of the column, wherein the column is closed at one end with a first filter, so that the particles will be retained by the filter while the liquid passes therethrough. After terminating the filling process, the other end of the column is closed with a second filter. According to the invention, the particle suspension is delivered via an inlet element which can be moved axially in relation to the end of the column an in which the second filter in mounted. During the filling process, the inlet element and the filter are held in a position in which the particle suspension is able to pass from the upper side of the filter and past its side-edge and into the interior of the column.

Abstract: Longitudinally collapsible apparatus for compacting packing material within a tubular liquid chromatography column. The apparatus includes a first support member, a second support member and a movable support member. The movable support member is releasably connectable to the second support member for support thereby. When released from the second support member, the movable member is adapted to ride on guide members extending between the first and second support members. A compression mechanism is supported on the movable support member to mote therewith to a longitudinally collapsed position for the apparatus. The compression mechanism comprises a reversible drive for an axially movable rod carrying a movable piston. With the movable support member secured to the second support member, the piston of the compression mechanism is movable in an end of the tubular column when the column is supported on the first support member.

Abstract: A structure comprising bodies having a functional surface property bonded to a substrate via a siloxane polymer adhesive. The structure may comprise a novel composition comprising a siloxane polymer having carbon bodies bonded thereto by direct carbon to silicon bonds. This composition may be used to bond carbon particles through a medium comprising the siloxane polymer to a vitreous, metal, plastic or other nucleophilic substrate. Alternatively, the bodies may comprise alumina, silicon, zeolite, organic polymers or other nucleophilic compositions, which are bonded directly to silicon atoms of the siloxane polymer. To bond carbon or other nucleophilic bodies to the substrate, the substrate is contacted with a mixture of the bodies and a hydrosiloxane polymer. The mixture is heated to cause the polymer to be bonded to the nucleophilic bodies, typically by C--Si, C--O--Si, Si--O--Si or Si--O--Al bonds, and to the substrate by reaction with the surface silanol or other nucleophilic groups.

Abstract: A separation column for chromatography, such as for liquid chromatography or supercritical fluid chromatography, comprises a separation tube made of a ceramic composite material and a stationary phase packed into the separation tube. The column has a high pressure stability and smooth inner surface leading to improved chromatographic properties.

Abstract: A separation medium for reversed-phase chromatography is prepared by polymerizing an aqueous vinyl monomer mixture to which a hydrophobic alkyl methacrylate with 3 or more carbon atoms in the alkyl group and a detergent have been added. The further inclusion of a vinyl monomer with a charged group in the reaction mixture produces a separation medium useful for reversed-phase electrochromatography. Performance of the polymerization in a capillary produces a continuous bed inside the capillary. An alternative for non-capillary separations, such as those conducted in larger diameter tubing, is the preparation of the medium in a vessel outside the tubing, followed by granulation of the polymer and placement of the granules in the tubing.

Abstract: Macromolecular species in a liquid sample are chromatographically separated in a separation medium formed by polymerization of monomers in an aqueous solution with a sufficient amount of crosslinking agent to cause aggregation and precipitation of the polymer chains. The medium is either formed in the column in which chromatography is to take place as a continuous although channeled bed, or in a separate reaction vessel and then transferred to the column in comminuted form as a packed bed. Improvements in the performance of the bed are achieved by compression of the bed.

Abstract: Chromatographically active stationary phases and adsorbents are made from sol-gels produced by the hydrolysis and condensation of alkoxysilanes that contain hydrolyzable alkoxy groups and non-hydrolyzable organo groups. The organo groups provide chromatographic activity in the resulting hybrid organic-inorganic material. Deposited as hybrid sol-gel coatings on solid supports, the coatings are heated to activate them. Hybrid organic-inorganic materials which contain different organic groups distributed in an inorganic network may be designed for the improved analysis of specific groups of compounds by the selection of the organo groups. Hydrocarbon mixtures may be advantageously analyzed by such hybrid materials.