Abstract: The invention relates to a device for positioning and holding one or more chromatographic column lengths being subjected to one or more jets of fluid to change the temperature, especially in a modulator for GC×GC. The device comprises one or more V-shaped seats in which the column is housed, and pushed within the groove.

Abstract: A system for controlling the flow rate into a chromatographic column is disclosed generally comprising communicating a fluid to the column through a transfer line, measuring the transfer line inlet pressure, determining the transfer line outlet pressure, and adjusting the applied pressure until the inlet and outlet pressures produce a desired flow rate for the transfer line outlet. In certain embodiments, the applied pressure is adjusted by controlling a proportional valve. In some embodiments, the outlet pressure is determined by measuring the pressure difference across the transfer line and calculating the transfer line outlet pressure from the measured inlet pressure and the pressure difference.

Abstract: Processes for removing inorganic impurities from HCl-containing gases, which processes comprise: providing a crude gas stream comprising hydrogen chloride and at least one inorganic component; introducing the crude gas stream into an adsorber bed; adsorbing at least a portion of the at least one inorganic component from the crude gas stream on the adsorber bed to form a purified HCl gas, and removing the purified HCl gas from the adsorber bed.

Abstract: The present invention relates to methods and systems for purifying gases, such as for example semiconductor process gases. The invention more particularly relates to fluid purification methods and systems having improved heat transfer capabilities and controls such that the purified fluid produced from the process contains reduced impurity levels and/or exhibits more uniform concentrations within the final product. In another aspect of the invention, the activation time for adsorbent beds used in such processes and systems can be reduced.

Abstract: An improved process for the separation of carbon dioxide from the flue gas of an oxy-combustion power plant is provided. An inlet stream containing carbon dioxide and oxygen is at least partially condensed in the reboiler of a stripping column. The condensed inlet stream is then separated in a separator, thereby producing a first liquid stream and a first gas stream. The first liquid stream is then separated into a top gas stream and a bottom liquid stream in the stripping column. The top gas stream is then warmed by indirect heat exchange in the heat exchanger.

Abstract: An improved process for the separation of carbon dioxide from the flue gas of an oxy-combustion power plant is provided. The flue gas is compressed, cleaned, cooled and dried. This flue gas stream contains carbon dioxide and oxygen, and is sent to a column. This column may be a distillation column or a stripping column. This column separates the inlet stream into a top gas stream and a bottom liquid stream. The top gas from the column is combined with the inlet stream.

Abstract: An improved gas chromatograph system includes a radiant source, an insert located to receive an output of the radiant source, and an analytic column wound on a concave surface of the insert so that successive coils of the wound analytic column are in direct contact with each other and exert an outward pressure on the concave surface of the insert such that the outward pressure minimizes a gap between the analytic column and the concave surface of the insert so as to minimize thermal gradients and maximize heat transfer to the analytic column.

Abstract: The present invention relates to a three dimensional preconcentrator and inlet heater. The preconcentrator consists of a substrate with passageways, a conductive material coated to the top and the bottom of the substrate and an adsorbent coating covering the entire substrate. This substrate is suspended in a holding frame by a connecting bridge. The preconcentrator may also include a resistor and a proportional-integral-differential controller. The device may be used inline with a detector and can be retrofitted to existing devices. An array of preconcentrators may also be formed. The invention also relates to methods of use of the preconcentrator and methods of manufacture. A method of use includes contacting an analyte and a preconcentrator, allowing the analyte to adsorb to the preconcentrator and then desorbing the analyte. A method of manufacture involves applying the adsorbent coating by misted chemical deposition.

Abstract: Methods and systems for cooling gas chromatography ovens that comprise a housing having a fluid entry and a sleeve positioned within the housing to provide a fluid gap between the inner surface of the housing and the outer surface of the sleeve, where the sleeve is coupled to the fluid entry, and where a cooling fluid from the fluid entry traverses the inner layer of the sleeve and thereafter the outer layer of the sleeve via the fluid gap. In one embodiment, the housing includes at least one adjustable fluid exit, and the fluid gap is in fluid communications with the fluid exit(s). The fluid entry and the sleeve can be concentric, and the sleeve can include a heating element. A fan can be positioned to drive the cooling fluid from the fluid entry.

Abstract: An automated system for processing a liquid test sample is provided.

Abstract: An analyte pre-concentrator for gas chromatography is disclosed generally comprising a tube having a restricted outlet and packed with an adsorbent, wherein the tube serves as the liner of a chromatographic injector, as an adsorbent trap coupled to a chromatographic column, and/or as an adsorbent trap coupled to a headspace sampler. Preferably, a heating device allows the tube to be heated. In a preferred embodiment, the analyte pre-concentrator further comprises a column isolating accessory so that a chromatographic column can be temporarily isolated from substances flowing through the tube.

Abstract: The invention relates to a gas chromatography apparatus with a cooling device, wherein the cooling device includes a closed cooling circuit containing a refrigerant, so that no refrigerant is wasted.

Abstract: Chromatography column assembly of the direct heating type, comprising at least a capillary column, at least a tubular structure which envelops the capillary column and is coaxial with it, means to directly heat the column, means to detect the temperature of the column and one or more electrically insulating covering elements, wherein the tubular structure comprises a plurality of tubular meshes each formed of a plurality of filaments woven together (FIG. 3).

Abstract: A method is disclosed for performing GC separations using a separation protocol including at least one negative temperature ramp, where the negative temperature ramp is controlled either by the introduction of a gaseous coolant at a controlled and adjustable rate or by the introduction of the coolant along with the application of microwave radiation to a column capable of absorbing microwave radiation, where the rate of coolant introduction or the rate of coolant introduction and radiation introduction is sufficient to achieve a desired rate of cooling.

Abstract: A non-planar microfabricated gas chromatography column comprises a planar substrate having a plurality of through holes, a top lid and a bottom lid bonded to opposite surfaces of the planar substrate, and inlet and outlet ports for injection of a sample gas and elution of separated analytes. A plurality of such planar substrates can be aligned and stacked to provide a longer column length having a small footprint. Furthermore, two or more separate channels can enable multi-channel or multi-dimensional gas chromatography. The through holes preferably have a circular cross section and can be coated with a stationary phase material or packed with a porous packing material. Importantly, uniform stationary phase coatings can be obtained and band broadening can be minimized with the circular channels. A heating or cooling element can be disposed on at least one of the lids to enable temperature programming of the column.

Abstract: Disclosed are systems and methods that include providing a vessel having an adsorbent disposed therein, the vessel having an inlet and an outlet for communicating a carrier gas through the vessel; determining a differential pressure between the inlet and the outlet for a known flow rate at the outlet; and, determining a geometric measure for the vessel based on a ratio of the known flow rate and the differential pressure. In some embodiments, the methods and systems can include a viscosity in the ratio, determining a flow rate at ambient pressure using a factor based on a ratio of a gas pressure at the output and ambient pressure, and/or, determining a flow rate at ambient temperature using a factor based on a ratio of a temperature at the output and ambient temperature.

Abstract: A gas chromatography/mass spectrometry system includes two sample introduction parts, a gas chromatography part having two columns, a column oven for housing the two columns in a parallel configuration, an interface part through which an outlet end of each of the two columns is inserted, and a mass spectrometry part. The mass spectrometry part has an ionization chamber to which the outlet ends of the columns inserted through the interface part are connected, a mass separation part, an ion detector, and a vacuum chamber for housing the ionization chamber, the mass separation part, and the detector. Because the outlet ends of the parallel columns are both connected to the ionization chamber, the carrier gas flow and line velocity are the same as though there is one column, thereby avoiding line stagnation. Since analyses can be performed selectively with a single system, results having high reliability and precision can be obtained.

Abstract: An Apparatus and method for two-stage chromatographic separation uses thermal modulation. The chromatographic column or modulation tube (1) has a loop structure such that two portions of modulation tube (1) can be thermally modulated simultaneously by at least one thermal modulation device, which device can have a cold gas source, jet tube (2), and a hot gas source, hot jet tube (5), to modulate the temperature of the portions (3, 4) of modulation tube (1).

Abstract: Devices for enhancing the sensitivity of a microsensor or any other micro device by providing on-line preconcentration. Microconcentrators that can be integrated with a sensor or a micromachined GC to enhance the signal to noise ratio can include a miniaturized sorbent trap fabricated on a microchip. The microconcentrator can be made on a silicon substrate so that a sensor can be integrated on the same chip. The microconcentrator is composed of at least one microchannel lined with a microheater for in-situ heating. Preconcentration may be achieved on a thin-film polymeric layer deposited above the heater in the microchannel. Rapid heating by the channel heater generates a “desorption pulse” to be injected into a detector or a sensor.

Abstract: This invention concerns a method and apparatus for vaporization injection of large volumes of liquid sample (substance to be analysed+solvent) introduced by a syringe needle into a heated vaporization chamber which is part of an injector coupled operatively to a device for gas chromatographic analysis. The sample is sent in the form of a liquid band traveling through the vaporization chamber at high speed until it reaches a stopping and vaporization device positioned adjacent to the inlet of a capillary to collect the vapors. In order to inject large volumes without modifying the vaporization chamber and without partial losses of the samples, the sample vapors, in splitless mode, are drawn up from the vaporization chamber into the capillary by virtue of the local action of volume contraction caused by recondensation of at least the solvent vapors in the capillary.

Abstract: A purge and trap concentrator and a method for drying a stream of sample gas in a gas analysis instrument. A dryer tube has an inlet that receives a stream of sample gas during a drying interval and receives a stream of dry gas during a regeneration interval. The dryer tube also has an outlet and an interior passageway between the inlet and an outlet. Support material comprising polymer sorbent is placed in the interior passageway and provides a support surface area for a hygroscopic coating comprising lithium chloride. A controller controls a heater to increase the temperature of the dryer tube to between 100 and 300 degrees centigrade during the regeneration interval and controls the heater to decrease the temperature of the dryer tube to below 100 degrees centigrade during the drying interval.

Abstract: The invention relates to a temperature-controlled injector for a chemical analysis unit, in particular a gas chromatograph, comprising an injector tube, which can be received by a receiving tube, having a cooling system, which surrounds the receiving tube, through which coolant can flow, which has coolant connections and which is designed as a metallic tube coil, and a resistance heating system for the injector tube, in which injector the receiving tube consists of a material of good thermal conductivity, is electrically insulating towards the outside, and the tube coil rests on the receiving tube, has an electrical resistance which is sufficient to rapidly heat the injector tube and can be acted on by current via electrical connection pieces.

Abstract: A coupling device connecting the output of a microchromatograph (?CG) to the input of a mass spectrometer (MS), said coupling device comprising a capillary tube with one end connected in sealed fashion to the source under vacuum of the mass spectrometer through the intermediary of an interface device, and with the other end connected to the output of the microchromatograph, in slack fashion, open to the atmosphere; the length and the diameter of the capillary tube being chosen such that the flow rate inside the capillary tube is very close to the flow rate at the output from the microchromatograph; the interface device being, furthermore, provided with heating means for very precise adjustment of the flow rate registered by the capillary.

Abstract: This invention relates to a modulator for use in gas chromatographic analysis, adopted for alternatively trapping and releasing fractions of solutes in a length of a capillary column within a chromatographic oven, characterized in that it comprises at least one nozzle placed to spray at least one jet in at least one corresponding place along said capillary column length, said nozzle(s) being connected each to a source of liquid CO2 via a related valve, and means for alternatively opening said valve(s) for a predetermined time, to cause a jet of liquid CO2 to impinge for said predetermined time on said column place and to leave the oven atmosphere to heat said column place after said predetermined time. The modulator can be used in a conventional GC system or in a two dimensional GC system, for modulating the analytes fed to the second capillary column.

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: The invention concerns a device for vaporizing injections of samples into a gas chromatography analysis device, comprising a vaporization chamber elongated lengthways and heated, as well as a syringe equipped with a needle, the device being of the type in which the introduction of the sample is carried out without prior vaporization of the sample within the needle, and also foresees at least one stop and vaporization means for the liquid inside the vaporization chamber. To improve the conditions of vaporization and the transfer of the sample, the distance between the free end of the needle and the stated stop and vaporization means for the liquid is greater than 55 mm (FIG. 1).

Abstract: A method and an apparatus for sample injection in gas chromatography increases the injecting volume of a sample, and can analyze any of high-boiling-point compounds, low-compounds boiling-point compounds, and compounds decomposed by heat. A sample is injected into a vaporizing chamber 6 having curved or crooked outer wall 6G and sample path S and formed of continuous inner walls 6H; the sample is temporarily held in the vaporizing chamber 6; then an objective compound is vaporized, and introduced into a separation column 17.

Abstract: A sub- to super-ambient temperature programmable microfabricated gas chromatography column enables more efficient chemical separation of chemical analytes in a gas mixture by combining a thermoelectric cooler and temperature sensing on the microfabricated column. Sub-ambient temperature programming enables the efficient separation of volatile organic compounds and super-ambient temperature programming enables the elution of less volatile analytes within a reasonable time. The small heat capacity and thermal isolation of the microfabricated column improves the thermal time response and power consumption, both important factors for portable microanalytical systems.

Abstract: A temperature programmable microfabricated gas chromatography column enables more efficient chemical separation of chemical analytes in a gas mixture by the integration of a resistive heating element and temperature sensing on the microfabricated column. Additionally, means are provided to thermally isolate the heated column from their surroundings. The small heat capacity and thermal isolation of the microfabricated column improves the thermal time response and power consumption, both important factors for portable microanalytical systems.

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 vaporization injector for gas chromatography analysis instruments, of the type including a vaporization chamber, heated or which may be heated, with a longitudinally elongated shape, a device for hermetically inserting the needle of a syringe containing the sample (substance to be analysed and solvent) into the chamber, a connection for feeding a carrier gas into the chamber and a gas chromatography capillary column with an upstream end open inside the vaporization chamber. In order to allow the vaporization of large sample volumes, the upstream end of the gas-chromatography column and the injection point of the sample into the vaporization chamber are both arranged adjacent to one of the longitudinal ends of the vaporization chamber and the feed connection for the carrier gas is located adjacent to the other end.

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: A method of reducing baseline instabilities in liquid chromatographic measurements is disclosed. A mobile phase comprising sample substances passes through a chromatographic column comprising a stationary phase, and subsequently through a detector. An additional solid body or liquid bath having a high heat capacity and heat conductance is coupled to the column and to an inlet capillary of the column such that the inlet capillary and the column are enclosed by said solid body or liquid bath. In that way temperature stabilization of the column and inlet capillaries is achieved and baseline variations due to temperature dependent adsorption of water at the stationary phase, in particular stationary phases with amino functional groups, are reduced.

Abstract: A method and an apparatus for chromatography are described, wherein at least one element in electrically conductive material is provided to heat the capillary column in a direct way and wherein the control of the temperature is carried out according to a mathematical model having a component of predictive type, or Feed Forward type, that describes the thermodynamic behavior of the assembly comprising the electrically conductive element and the column at least as a function of the thermal resistance and the thermal capacity of the assembly thus constituted in order to regulate the supply of electrical power supplied to the conductive element.

Abstract: A thermal conductivity detector includes not only a thermal conductivity detector cell disposed so as to be heated by heat transmitted from a first heater block and a column connector connected to the detector cell and to a column of a chromatograph but also a second heater block for heating the column connector. The heaters for individually heating these two heater blocks are controlled simultaneously and in synchronism by a single temperature controller according to the temperature of the first heater block for heating the detector cell.

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: 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 method and an apparatus for chromatography are described, wherein at least one element in electrically conductive material is provided to heat the capillary column in a direct way and wherein the control of the temperature is carried out according to a mathematical model having a component of predictive type, or Feed Forward type, that describes the thermodynamic behavior of the assembly comprising the electrically conductive element and the column at least as a function of the thermal resistance and the thermal capacity of the assembly thus constituted in order to regulate the supply of electrical power supplied to the conductive element.

Abstract: A gas chromatography system with suspended tubular separation column(s) in an enclosed convection oven where a gas medium is heated by at least two electrically powered heaters. A kit to modify gas chromatographic ovens for operation with at least two electrically powered heaters. The heaters are positioned to promote even heating along the length of the column(s) and shielding of the column(s) from radiant heat. The heaters can provide faster heating rates at elevated temperatures.

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 method and device for vaporization injection in which there is at least one constriction between the end of the sample injection needle or tube and the interior of the heated vaporization chamber. The terminal part of the needle or tube can be heated to improve nebulisation of the sample and therefore its vaporization speed.

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 a carrier gas into a first polar separation column which retains higher-boiling components and water and passes low-boiling components, the latter 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 cryofocussing.

Abstract: A temperature programmed module for use in a gas chromatograph. The module has micropacked column and inner and outer jacket tubes. The inner jacket tube surrounds the column to provide a space between the that tube and the column. The outer jacket tube surrounds the inner jacket tube to provide a space between the two jacket tubes. Air which has a controlled temperature flows only in the space between the two jacket tubes when it is desired to heat the column. Air flows in both spaces when it is not desired to heat the column. The temperature of the air is controlled. The module along with the sample injection valve and flame ionization detector are in an enclosure that is not temperature controlled. The air that flows in both spaces also flows in the enclosure to keep the heat from the valve and the flame ionization detector from heating the column.

Abstract: A preferred sample introduction apparatus includes a wall that defines a channel, with the channel being configured to receive a sample and being adapted to engage in fluid communication with the separation column of a chromatographic apparatus. Preferably, a coating of semi-conductive material is arranged adjacent to at least a portion of the wall. Additionally, a heater controller is provided which electro-magnetically communicates with the coating. So configured, the coating, in response to receiving energy from the heater controller, increases in temperature, thereby increasing a temperature of the sample.

Abstract: A device for analyzing organic compounds, particularly in aqueous and gaseous samples, constituted by a duct which is supplied in input by a gas whose pressure can be controlled by means of a regulator connected to a capillary column which is connected in output to a detector for the organic compounds; an adsorbent polymer immersed in a container is interposed between a first portion and a second portion of the capillary column, and the device comprises, between the second portion and a third portion, means for concentrating the organic compounds; the container contains an aqueous or gaseous sample which interacts with the adsorbent polymer adapted to extract the organic compounds conveyed by the gas in passing through the adsorbent polymer toward the concentration means in order to be measured by the detector.

Abstract: The invention relates to a gas chromatograph having a temperature-controlled injector for containing a vaporizer tube with chemical substances, thereon to be analyzed via a gas chromatography column, which temperature-controlled injector and vaporization tube can be heated by an electric resistance coil type of heating unit and can be cooled by a cooling unit, wherein the cooling unit has a cooling coil (7) which surrounds the heating unit and which is provided via a feedline and a return line (8, 9) with an external source of liquid, cooled coolant, with provision of a pump (11) for circulating the coolant and of a drain valve for draining the cooling coil.

Abstract: Rapid characterization and screening of polymer samples to determine average molecular weight, molecular weight distribution and other properties is disclosed. Rapid flow characterization systems and methods, including liquid chromatography and flow-injection analysis systems and methods are preferably employed. High throughput, automated sampling systems and methods, high-temperature characterization systems and methods, and rapid, indirect calibration compositions and methods are also disclosed. The described methods, systems, and devices have primary applications in combinatorial polymer research and in industrial process control.

Abstract: Method and apparatus for analyzing a breath sample provide user-friendly operation and analysis. The method and apparatus provide automatic operation and coordination of operation of an absorbent sample tube, including desorbing means, a chromatographic precolumn, a chromatographic main column, a detector, a data processor, a sample receiving tube for receiving exhaled breath sample, a sample loop for aspirating a prescribed quantity of breath sample from the sample receiving tube, a sample valve, a standard gas reservoir, and a standard gas valve. All of the foregoing are operated automatically in such that start cycles, detector cycles, fault detection cycles, standardizing, analysis, shutdown and end cycles are performed in a way which allows straightforward and simple measurement of breath sample by a user.