Abstract: A denuder assembly is adapted for the collection and removal of a gaseous analyte from a sample gas. The denuder includes a housing including an internal cavity, a sample gas inlet fluidly coupled with a sample gas source, a denuder liquid inlet fluidly coupled with a denuder liquid source, a barrier sheet extending across the internal cavity and separating the internal cavity into a liquid reservoir and a gas flow-through channel fluidly coupled with and downstream of the sample gas inlet, and a denuder liquid disposed in the liquid reservoir and permeating the barrier sheet to coat the gas-channel surface of the barrier sheet thereby allowing the denuder liquid on the gas-channel surface to contact the sample gas flowing within the gas flow-through channel and allowing the analyte to diffuse through the barrier sheet into the liquid reservoir.

Abstract: An apparatus for pressurizing a removable chromatographic cartridge, comprises radial pressure means acting onto the side surface of the chromatographic cartridge, and axial pressure means acting onto the ends of the chromatographic cartridge. During use, the axial and radial pressure means are simultaneously active.

Abstract: An auxiliary modular oven assembly for use with a gas chromatograph. The auxiliary oven assembly is comprised of a housing, an oven compartment, a heater, at least one sampling valve, at least one fixed volume sample loop, and at least one chromatograph column or column trains, wherein the column or column trains contains a material capable of causing the separation of chemical components of a chemical sample at elevated temperatures.

Abstract: A chromatography column suitable for small-scale laboratory use as a column tube resembling that of a syringe and a movable plunger which slides in the column tube. End filter arrangements are mounted by direct integration, e.g. melt-bonding of glass, into these components. A tubular stem providing an internal flow conduit to the end filter arrangement at the front end of the plunger is also integrally bonded behind the permeable filter portion. By making all of these operational components out of a formable, melt-bondable material, preferably glass which can also make sliding seals with itself, the resulting chromatography column is simple to use and unlikely to leak by comparison with conventional laboratory columns which use many discrete components.

Abstract: An apparatus for use in liquid chromatography involves a column filled with media bounded axially by first and second porous plates. The column has an inlet end with an inflow region between the inlet end and the first porous plate. The column also has an outlet end with an outflow region between the outlet end and the second porous plate. The inflow region may be substantially longer than the outflow region. The porous plates may be moveable under pressure so as to compress the media.

Abstract: A device is provided for enhancing the sensitivity of a microsensor (or any other micro device) by providing on-line preconcentration. A microconcentrator is provided on a silicon substrate that can be integrated with a sensor or a micromachined GC to enhance the signal to noise ratio. In one embodiment the microconcentrator comprises a miniaturized sorbent trap fabricated on a microchip. In a preferred embodiment the microconcentrator is made on a silicon substrate so that a sensor can be integrated on the same chip. In practice the microconcentrator is put on-line with a sample stream and may be operated at a fixed frequency. The microconcentrator is composed of at least one microchannel etched in silicon. The channel is lined with a microheater for in-situ heating. In a most preferred embodiment preconcentration is done on a thin-film polymeric layer deposited above the heater in the channel.

Abstract: A capillary column (10) includes a tube structure having inner walls (14) and a sol-gel substrate (16) coated on a portion of inner walls (14) to form a stationary phase coating (18) on inner walls (14). The sol solution used to prepare the sol-gel substrate (16) has at least one baseline stabilizing reagent and at least one surface deactivation reagent resulting in the sol-gel substrate (16) having at least one baseline stabilizing reagent residual and at least one surface deactivating reagent residual. A method of making the sol-gel solution is by mixing suitable sol-gel precursors to form the solution, stablizing the solution by adding at least one baseline stabilization reagent, deactivating the solution by adding at least one surface deactivation reagent to the solution, and reacting the solution in the presence of at least one catalyst.

Abstract: A micro-gas chromatograph column is formed by texturing a channel into a plurality of green-sheet layers, which are then sintered together to form a substantially monolithic structure. A thick-film paste may be added to the channel textured in the green-sheet layers to provide a porous plug sintered in the micro-gas chromatograph column in the substantially monolithic. A thermal conductivity detector is formed in the substantially monolithic structure by depositing a conductive thick-film paste on the surface of one of the green-sheet layers to define a resistor in an exit channel of the micro-gas chromatograph column.

Abstract: An assembly consisting of a winding structure 1 around which a chromatographic column 6 can be wound, and an information carrier 7 which can be connected to said winding structure 1. This assembly offers a rigid and convenient means to handle one or two chromatographic columns of longer lengths. The information carrier 7 contains the chromatographic column identification information as well as several tools, such as a tool 13 to hold one or two chromatographic column connectors 11, a ruler to measure column insertion lengths and clips 12 to hold column ends, and clips to hold column extensions.

Abstract: A material is provided for capturing a chemical substance comprising fibers which carry metal alkoxide particles on the surfaces thereof. The metal alkoxide particles are made from an oligosilica, an oligozirconia, an oligotitiania, or the like. The fibers may include inorganic fibers, regenerated fibers and/or synthetic fibers. The material for capturing a chemical substance is produced by a method comprising steps of subjecting the fibers to a surface treatment for facilitating adhesion of the metal alkoxide particles to the surfaces of the fibers, forming the metal alkoxide particles on the surfaces of the fibers, and fixing the metal alkoxide particles to the surfaces of the fibers. A chemical substance-capturing tube, capable of capturing a trace of a chemical substance in a liquid or a gas, can be produced by placing the fibers, i.e., the material for capturing a chemical substance, in a hollow tube.

Abstract: In an open capillary column, a stationary phase is formed on the inner wall of a capillary tube. This stationary phase comprises a number of pores on the surface of the capillary tube, and each of pore has an expanded hollow in the stationary phase. A manufacturing method of an open capillary column comprises the steps of giving alkaline treatment to an inner wall of an open capillary tube, applying one of oligo silica, oligo zirconia and oligo titania on the inner wall, filling the open capillary tube with alkaline solution to form one of a silica layer, a zirconia layer and titania layer, discharging the alkaline solution and heat-treating the capillary tube to form a base of a stationary phase. The open capillary column of the present invention comprises a stationary phase having a very large surface area. It is useful for a separation analysis field such as liquid chromatography and electrochromatography.

Abstract: A new method for fabricating a silicon chromatographic column comprising through-substrate fluid ports has been developed. This new method enables the fabrication of multi-layer interconnected stacks of silicon chromatographic columns.

Abstract: A method for the separation of hydrogen ion, characterized in that a substance having a conjugate base (A−) of an acid (HA) as a functional group is used as a stationary phase, and an electrolyte containing a cation having a larger ion exchanging force than that of hydrogen ion is used as an eluent. The method allows the selective separation of hydrogen ion and the quantitative analysis thereof with high precision.

Abstract: Guard columns for high-pressure liquid chromatography (HPLC) apparatuses. These guard columns can be removable and/or metallic guard columns. Further, all of the outlet of the guard column can substantially engage the inlet of an HPLC column in the HPLC apparatus. Also, an HPLC apparatus that includes a guard column, a hand-tightened top end fitting at a first end of the HPLC apparatus and a hand-tightened bottom end fitting at a second end of the HPLC apparatus.

Abstract: A glass-silicon column that can operate in temperature variations between room temperature and about 450° C. The glass-silicon column includes large area glass, such as a thin Corning 7740 boron-silicate glass bonded to a silicon wafer, with an electrode embedded in or mounted on glass of the column, and with a self alignment silicon post/glass hole structure. The glass/silicon components are bonded, for example be anodic bonding. In one embodiment, the column includes two outer layers of silicon each bonded to an inner layer of glass, with an electrode imbedded between the layers of glass, and with at least one self alignment hole and post arrangement. The electrode functions as a column heater, and one glass/silicon component is provided with a number of flow channels adjacent the bonded surfaces.

Abstract: A new class of miniaturized gas chromatographic columns has been invented. These chromatographic columns are formed using conventional micromachining techniques, and allow packed columns having lengths on the order of a meter to be fabricated with a footprint on the order of a square centimeter.

Abstract: The present invention relates to an autosampler device useful in high pressure liquid chromatography (HPLC), and more particularly to a device useful for the automated introduction of small sample volumes into a HPLC system. Methods of analyzing low abundant protein samples using such a device are also included.

Abstract: An apparatus for collecting and detecting chemicals contained in a fluid includes a sorbent element, at least one chemical sensor, a first pump for pumping fluid through the sorbent element and a second pump for pumping fluid to the chemical sensor. The sorbent element contains a sorbent material and a heating element. The first pump pumps fluid into the sorbent element thereby collecting the chemicals on the sorbent material. The heating element provides heat to the sorbent element to desorb the chemicals from the sorbent material. The chemicals desorbed from the sorbent material are then pumped out of the sorbent element and to the chemical sensor. The sorbent material may have a cavity therein with the heating element located in that cavity. Alternatively, the heating element may be interposed between the enclosure and the sorbent material.

Abstract: A material is provided for capturing a chemical substance comprising fibers which carry metal alkoxide particles on the surfaces thereof. The metal alkoxide particles are made from an oligosilica, an oligozirconia, an oligotitiania, or the like. The fibers may include inorganic fibers, regenerated fibers and/or synthetic fibers. The material for capturing a chemical substance is produced by a method comprising steps of subjecting the fibers to a surface treatment for facilitating adhesion of the metal alkoxide particles to the surfaces of the fibers, forming the metal alkoxide particles on the surfaces of the fibers, and fixing the metal alkoxide particles to the surfaces of the fibers. A chemical substance-capturing tube, capable of capturing a trace of a chemical substance in a liquid or a gas, can be produced by placing the fibers, i.e., the material for capturing a chemical substance, in a hollow tube.

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 system for column-based separations, comprising: a) a fluid passageway, the fluid passageway comprising a column chamber and a flow path in fluid communication with the column chamber, the flow path being obstructed by a retaining material permeable to a carrier fluid and impermeable to a column matrix material suspended in the carrier fluid, the flow path extending through the column chamber and through the retaining material, the flow path being configured to form a packed column within the column chamber when a suspension of the fluid and the column matrix material is flowed along the flow path; and b) the fluid passageway extending through a valve intermediate the column chamber and the retaining material.

Abstract: The invention provides a gas chromatography method for analyzing materials vaporizable in a gas chromatograph system, the method including filling a sample injection device with a sample of the compounds to be analyzed; transferring the sample compounds into an analytical separation column with a transfer gas; passing a carrier gas inside the analytical separation column for time separation of the sample compounds; controlling the temperature of the column for achieving separation of the sample compounds; transferring the vaporized sample compounds eluted from the column into a flame ionization detector; providing the gases required for the operation of the flame ionization detector, and analyzing the data output of the flame ionization detector for analysis of the sample compounds, wherein the gases required for the operation of the gas chromatograph system are produced by water electrolysis.

Abstract: A passive air sampler is designed to facilitate emptying granular or particulate adsorbent from it directly into a thermal desorption tube or other vessel for use in an analytical instrument. The preferred form has an adsorbent container in a conical or funnel-like shape.

Abstract: A separation column for a gas chromatograph that includes a block of electrically insulating material having a channel located between two strips of thermoelectric material spaced from the channel by strips of electrically insulating material. Electrodes are connected to opposite ends of the strips of thermoelectric material. More specifically, each strip of thermoelectric material has two layers of dissimilar material to enable the strips to provide selective heating and cooling depending on the direction of current flow through the strips.

Abstract: A separation column for a gas chromatograph that includes a block of electrically insulating material having a channel located between two strips of thermoelectric material spaced from the channel by strips of electrically insulating material. Electrodes are connected to opposite ends of the strips of thermoelectric material. More specifically, each strip of thermoelectric material has two layers of dissimilar material to enable the strips to provide selective and cooling depending on the direction of current flow through the strips.

Abstract: An explosion-proof apparatus includes a pressure resistant explosion-proof case, heater, manifold, and analyzer unit. The heater is disposed in the pressure resistant explosion-proof case. The manifold is heated by the heater in the pressure resistant explosion-proof case and supplies heat from the heater to an outside of the pressure resistant explosion-proof case by heat conduction. The analyzer unit is disposed outside the pressure resistant explosion-proof case in contact with the manifold, and is heated by heat supplied from the manifold.

Abstract: A separation column for analyzing a gas includes a capillary which is filled with a separation material. In order to be able to use the separation column in a microsystem technology, spheres are used as the separation material. The spheres all have the same diameter. The diameters of the spheres are slightly smaller than the internal diameter of the capillary or are matched to the internal diameter of the capillary. The spheres are provided inside the capillary in a row one behind the other.

Abstract: A measuring and evaluating device for the analysis of gases is described. The device has an exchangeable gas analyzer, which is of small dimensions. The gas analyzer is a module connected directly from the outside to a central unit, which is likewise of small dimensions and into which at least one evaluating unit and a display unit are integrated. Fitted releasably into the gas analyzer are one or more plates, into which at least one separating channel is respectively integrated. Each gas analyzer is provided with at least one sample injector, which can be connected to at least one separating channel. At least one detector is connected downstream of each separating channel.

Abstract: A method of thermally modulating a tubular member carrying a sample substance therethrough is provided. The method includes the steps of (a) directing at least one gas stream toward a tubular member in a direction substantially transverse to the tubular member, wherein the temperature of the gas stream differs from the temperature of the tubular member; and (b) varying the gas flow rate of the at least one gas stream as a function of time to thermally modulate the tubular member. An apparatus is also provided for thermal modulation and includes: a tubular member for carrying a sample substance therethrough in a fluid medium; a gas stream source for directing a gas stream toward the tubular member in a direction substantially transverse to the tubular member; a gas stream supplied from the source with a temperature that differs from the temperature of the tubular member; and a gas stream of varying gas flow rate supplied from the gas stream source as a function of time to thermally modulate the tubular member.

Abstract: A discharge gas containing PFC gas including CF4 and NF3 generated from a manufacturing process (10) is concentrated at a concentrator (18) and then chromatographically separated at a chromatographic separator (20) with nitrogen as a carrier gas. In this manner, CF4 and NF3 within the PFC gas can be separated. In particular, because the gas is once concentrated at the concentrator (18), chromatographic separation can be efficiently achieved. By independently concentrating CF4 and NF3 obtained by the chromatographic separation, high purity gas constituents of the PFC gas can be obtained, and reused at the manufacturing process (10).

Abstract: A capillary column comprising a capillary of which the inner diameter is less than 1000 &mgr;m and a continuous porous silica gel which uniformly fills the capillary, said silica gel containing both continuous through pores having diameters ranging from 0.5-5 &mgr;m and mesopores having diameters ranging from 2-50 nm.

Abstract: A chromatography column with filters having minimal volume. A stamped screen disk is coated with fluorocarbon polymer on both sides, leaving a center area open. The fluorocarbon polymer coating serves as a gasket, providing reliable sealing for pressure up to approximately 10000 psi. The chromatography column comprises a fitting having an internal cavity. A fluorocarbon polymer coated screen is placed within the cavity. A threaded capillary tubing is screwed inside the cavity. At the end of the capillary lies a compression screw solvent tubing connection.

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

Abstract: A micro-gas chromatograph column is formed by texturing a channel into a plurality of green-sheet layers, which are then sintered together to form a substantially monolithic structure. A thick-film paste may be added to the channel textured in the green-sheet layers to provide a porous plug sintered in the micro-gas chromatograph column in the substantially monolithic. A thermal conductivity detector is formed in the substantially monolithic structure by depositing a conductive thick-film paste on the surface of one of the green-sheet layers to define a resistor in an exit channel of the micro-gas chromatograph column.

Abstract: Capillary column oxidation in gas chromatography systems, particularly of polyimide clad columns, is a major cause of column failure and it limits the maximum temperature at which columns can be used. A gas chromatography column oven system is described which utilizes inert gas to substantially eliminate column oxidation thereby increasing column thermal stability. These column oven systems thus increase column lifetime and maximum operating temperature. The column oven systems comprise pneumatically sealed oven enclosures with sealed access ports, sealed sample line ports, and inlet and outlet gas ports to which are connected an inert gas supply and an exhaust gas control system respectively.

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 points and draw-off points are shifted by the same number of columns or column sections and advantageously 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 points and draw-off points of at least one 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.

Abstract: A two-dimensional gas chromatograph with a primary column (14) and dual secondary columns (26, 28) is described. Flow rates in the primary column are less than those in the secondary columns due to an accumulation valve (16). Typically the ratio of second and third column flow capacities combined to primary column flow capacities between about 10 to 1 and 30 to 1. Volatile organic compounds are detected in environmental samples of air water, soil and in body fluids of animals and humans.

Abstract: The invention relates to a method of trace analysis of organic compounds which calls for the steps of setting a test piece in a flow cell, and thereafter removing organic compounds from the test piece by heating it at high temperature in an oven. The compounds are concentrated in a trap tube and then removed from the trap tube and carried into a concentrating/inlet unit, such as a thermal desorption cold trap injector. In this unit, cryofocusing of the compounds is performed, and then the organic compounds are introduced into a gas chromatograph to be analyzed therein, wherein a part of the purified inert gas is caused, except during the process of trapping the organic compounds, to flow into the flow cell from the direction opposite the direction from which the gas flows along the trapping line.

Abstract: A separation-column unit includes a support plate having a groove formed therein on one side and running, for example, in the form of a spiral, and having a cover plate which bears against this side. In order to achieve the high separation capacity combined with a high load-bearing capacity with regard to the amount of sample flowing through, the depth (d) of the groove is preferably at least three times greater than its width. The base of the groove preferably has a rounded cross section, it being possible for the cover plate to contain a corresponding channel.

Abstract: A headspace sampling system monitors materials in wastewater. The headspace sampling system comprises a sample receptacle that can contain a wastewater sample; a sparger chamber vapor column; a sample receptacle cover assembly that connects the sparger chamber vapor column to the sample receptacle; a sparger tube; at least one sensing device; and at least one analytic device. The sparger tube and the sample receptacle define a headspace. The sparger chamber vapor column is in communication with the sample receptacle and is closed by a sparger chamber vapor column cover at a second end that is opposed to the sample receptacle. The sparger tube extends into the sample receptacle and the wastewater sample in the sample receptacle. The sparger tube is connected to a source of inert gas at a first end opposed to the sample receptacle and comprises a dispersion device at an end opposed to the first end. The sensing device is disposed in the headspace sampling system in the headspace.

Abstract: An apparatus for use in liquid chromatography involves a column filled with media bounded axially by at least one porous member. The column has an inlet end with an inflow region between the inlet and a porous member. The inflow region may be sufficiently long so that a chromatography sample module may be disposed therein. The column may be sufficiently long so that a chromatography sample module may be disposed therein. The column may also have an outlet end with an outflow region between the outlet end and a second porous member. The inflow region may be substantially longer than the outflow region. The porous members may be moveable relative to the column.

Abstract: A separation column for analyzing a gas includes a capillary which is filled with a separation material. In order to be able to use the separation column in a microsystem technology, spheres are used as the separation material. The spheres all have the same diameter. The diameters of the spheres are slightly smaller than the internal diameter of the capillary or are matched to the internal diameter of the capillary. The spheres are provided inside the capillary in a row one behind the other.

Abstract: The basic structure of a PTV (programmed temperature vaporizer) injector has been considerably modified so that is can be used for the direct coupling of liquid chromatography in normal phase or reverse phase, and gas chromatography and also for the introduction of high volumes in gas chromatography. The glass tube of the injector is filled with an adsorbent. By means of a system of valves and tubes or capillary tubes, the previously selected fraction of liquid chromatography is transferred to the injector, said fraction coming in through the same extremity for introducing the gas chromatography column. The eluent is entrained by a gas stream through the adsorbent, wherein are retained the solutes, and the solvent is removed through a tube or capillary tube introduced in the injector through the opposite extremity. Thereafter, the solutes are desorbed thermally passing to the chromatography column.

Abstract: Using a distillation separator, a gas to be treated is separated into a plurality of gas groups having different boiling points. Then, the specific gases included in each of the plurality of gas groups separated at the first separating means and having similar oiling points are separated using a chromatographic separator. In this manner, specific gases can be separated from the gas to be treated containing a plurality of specific gases.

Abstract: A chromatography column is disclosed. The large diameter chromatography column comprises a column body with threaded end portions. At each of the end portions, a respective filter housing is disposed. A respective threaded end cap is threaded onto each of the threaded end portions. Each of the end caps has holes for receiving a plurality of mechanical fasteners. The mechanical fasteners are installed into each end cap and apply pressure against the filter housing which forces the filter housing against the face of the column, thus sealing it. When the need to open the column arises, the mechanical fasteners can be easily loosened to release the tension on the thread between column body and end cap. After this, the end cap can be unscrewed with minimal torque.

Abstract: A quarter turn quick connect fitting assembly (10) for connecting miniature fluid conduits, such as tubing, includes a first fitting (12) having radially projecting pins (28) and a second fitting (14) located within a rotatable quarter turn nut (16) having spiral grooves (48) which receive the pins. The first fitting defines a central passage (26) and the second fitting defines a central passage (42) which may each be configured to slidably receive a hollow tube set (104), or to threadably receive an externally threaded mating fitting. The quarter turn quick connect fitting can be configured to attach to the end of a column, and can include an adapter (158), which houses a guard column (160), or a frit (188) for filtering the fluid passing through the quarter turn quick connect fitting assembly.

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 discharge gas containing PFC gas including CF4 and NF3 generated from a manufacturing process (10) is concentrated at a concentrator (18) and then chromatographically separated at a chromatographic separator (20) with nitrogen as a carrier gas. In this manner, CF4 and NF3 within the PFC gas can be separated. In particular, because the gas is once concentrated at the concentrator (18), chromatographic separation can be efficiently achieved. By independently concentrating CF4 and NF3 obtained by the chromatographic separation, high purity gas constituents of the PFC gas can be obtained, and reused at the manufacturing process (10).

Abstract: A method of thermally modulating a tubular member carrying a sample substance therethrough is provided. The method includes the steps of (a) directing at least one gas stream toward a tubular member in a direction substantially transverse to the tubular member, wherein the temperature of the gas stream differs from the temperature of the tubular member; and (b) varying the gas flow rate of the at least one gas stream as a function of time to thermally modulate the tubular member.

Abstract: The invention relates to gas chromatography analysis of a sample having components to be investigated and water contained therein, which after thermodesorption is separated and analyzed, the thermodesorbed sample being transferred by means of carrier gas into a first polar separation column which retains higher-boiling components and water and passes low-boiling components, the lafter being led, past a branching point which leads, on the one hand, to a second polar or non-polar separation column and, on the other hand, to the non-polar separation column, to the non-polar separation column in a fashion excluding access to the second polar or non-polar separation column, after which higher-boiling components and water are transferred to the second polar or non-polar separation column in a fashion excluding access to the non-polar separation column, water being eliminated upstream of the second polar or non-polar separation column by means of cryofocussing.

Abstract: A diffusion collector for analytes contained in liquid phases includes a planar housing which has channel-like cavities. A collecting phase is inserted into these channel-like cavities. The collecting phase is covered by a diffusion membrane through which the analyte can pass. The housing has at least one incoming pipe and one outgoing pipe allowing the fluid medium to pass through the channel-like cavities perpendicular to the direction of diffusion.