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: A gas chromatography system having a computer-controlled pressure controller that delivers pressurized pulses to a column junction point of two series-coupled columns having different stationary-phase chemistries and a method of using the same. Each pressurized pulse causes a differential change in the carrier gas velocities in the two columns, which lasts for the duration of the pressurized pulse. Whereby, the pressurized pulse selectively increases the separation of a component pair that exhibits separation at the exit of the first column, but otherwise co-elutes from the column ensemble.

Abstract: A gas chromatography system having a computer-controlled venting valve system that delivers pressurized pulses to a column junction point of two series-coupled columns having different stationary-phase chemistries and a method of using the same. Each pressurized pulse causes a differential change in the carrier gas velocities in the two columns, which lasts for the duration of the pressurized pulse. Whereby, the pressurized pulse selectively increases the separation of a component pair that exhibits separation at the exit of the first column, but otherwise co-elutes from the column ensemble.

Abstract: A gas chromatography system having a computer-controlled venting valve system that delivers pressurized pulses to a column junction point of two series-coupled columns having different stationary-phase chemistries and a method of using the same. Each pressurized pulse causes a differential change in the carrier gas velocities in the two columns, which lasts for the duration of the pressurized pulse. Whereby, the pressurized pulse selectively increases the separation of a component pair that exhibits separation at the exit of the first column, but otherwise co-elutes from the column ensemble.

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 separator and having similar boiling 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: This invention provides a reduced power consumption gas chromatograph system (10) which includes a capillary gas chromatograph column member (12) which contains a chemical sample to be analyzed. The gas chromatograph system further includes a heating mechanism (16) which extends throughout the length of the capillary gas chromatograph column member (12) and surrounds both the member (12) and a temperature sensing mechanism (14) which is mounted adjacent to the column member (12). The temperature sensing mechanism (14), the heating mechanism (16) and the column member (12) form a chromatograph column assembly (20) which includes a coiled section (28) where the components are tightly packed with respect to each other and allows for a reduced power consumption for temperature programming miniature gas chromatography column assemblies.

Abstract: A high-sensitivity, separation microcolumn assembly for a microgas chromatograph and the like is provided. The assembly has an ultra-low mass complete with integrated heaters. The assembly uses multiple zones for temperature control, and microstructures that permit very rapid heating and cooling of the microcolumn.

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 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: A discharge gas containing PFC gas including CF4 and NF3 generated from a manufacturing process (10) is adsorbed at an adsorbing device (18) and then desorbed using nitrogen as a purge gas. A desorbed gas with CF4 and NF3 concentrated can be obtained in this manner. The desorbed gas is then supplied to a chromatographic separator (20) for chromatographic separation 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 adsorbing device (18), chromatographic separation of the gas constituents can be efficiently performed. 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: Methods and apparatus are disclosed which are useful for detecting the presence of various pesticides, including aryl pyrazoles such as fipronil. Pesticide residues are extracted from a variety of samples, including soil and/or water samples using techniques well known to those of skill in the art. The samples are then concentrated, and transferred to an solid phase extraction cartridge. The SPE cartridge includes activated charcoal, silica gel, magnesium-silica gel and an amino-functional silica sorbent, or suitable equivalents thereof. After cleanup, the eluate containing the analyte of interest can be concentrated to a standard sample size and the amount of pesticide residues quantitated. In a preferred embodiment, the column chromatography materials are assembled in a solid phase extraction cartridge with frits between the chromatography materials. This facilitates the use of the cartridge in standard automated analytical equipment, for example, robotic equipment.

Abstract: The present disclosure relates to a gas chromatograph having a plurality of layers or channels. The chromatograph typically comprises an inlet that receives a sample to be analyzed, a column disposed in each of the plurality of chromatograph layers, each column being in fluid communication with and downstream from the inlet and having a stationary phase coating its inner surfaces, and a detector in fluid communication with and downstream from at least one of the columns. In a preferred arrangement, the chromatograph includes a pre-column disposed in each of the chromatograph layers upstream of the columns, each pre-column being in fluid communication with the inlet and having a stationary phase coating its inner surfaces.

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: 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: 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: A multiple parallel hand-held gas chromatograph (GC) system which includes several independent GCs. Each independent GC has its own injector, separation column, detector and oven and the GCs are mounted in a light weight hand-held assembly. Each GC operates independently and simultaneously. Because of different coatings in different separation columns, different retention times for the same gas will be measured. Thus, for a GC system with multiple parallel GCs, the system can measure, in a short period, different retention times and provide a cross-reference in the determination of the measured gas and to become a two-dimensional system for direct field use.

Abstract: This invention provides a reduced power consumption gas chromatograph system (10) which includes a capillary gas chromatograph column member (12) which contains a chemical sample to be analyzed. The gas chromatograph system further includes a heating mechanism (16) which extends throughout the length of the capillary gas chromatograph column member (12) and surrounds both the member (12) and a temperature sensing mechanism (14) which is mounted adjacent to the column member (12). The temperature sensing mechanism (14), the heating mechanism (16) and the column member (12) form a chromatograph column assembly (20) which includes a coiled section (28) where the components are tightly packed with respect to each other and allows for a reduced power consumption for temperature programming miniature gas chromatography column assemblies.

Abstract: A sample concentration device is provided in which a gaseous sample is concentrated by cooling a portion of a gas transfer line through which the sample is introduced into a detecting apparatus, such as a gas chromatograph or the like. The device is characterized by a cooling device for cooling a portion of the gas transfer line, which is housed in a constant temperature chamber, by spraying a coolant from a nozzle facing the portion of the gas transfer line, and by a gas flow device for creating a substantially dry gas flow through the nozzle to prevent the nozzle from becoming plugged with ice formed by freezing of moisture in the air inside the constant temperature chamber when the coolant spray is stopped. An outer jacket surrounding a portion of the gas transfer line which is subjected to cooling is also disclosed.

Abstract: A novel chromatograph is provided. The chromatograph includes an analytical column which is a channel with a rectangular cross-section. Integrated with the chromatograph are a sample collection channel and a restriction channel. The column, sample collection channel, and restriction are all part of a single unitary microstructure. The microstructure is manufactured by irradiating and etching a material subject to synchronized x-ray radiation. The device will either be made of the actual etched material, or the etched material will be used as a mold or model to fabricate the chromatograph. A method of using the device is also disclosed.

Abstract: In a denuder (2) serving as a gas collection apparatus, an absorption liquid supply tube (4) for spraying absorption liquid from a nozzle (4a) to the inner wall of a denuder pipe (2a) is provided at the upper portion of the denuder pipe (2a). A sample atmospheric air supply tube (7) for supplying sample atmospheric air into the denuder (2) is provided at the lower portion of the denuder pipe (2a). On the inner wall of the denuder pipe (2a) is formed a photocatalyst thin film layer (13) containing photocatalyst which is optically excited to be made super-hydrophilic upon irradiation of light having specific wavelengths (for example, ultraviolet rays) thereto.

Abstract: An apparatus and a method are described for forming a chemical modulation of a substance present in a fluid stream, which utilize a movable device, such as a movable heater, to induce changes in the retention of a chemical substance flowing through the modulator tube. The modulator tube has an inlet, a first portion in communication with the inlet, a second portion in communication with said first portion, and an outlet in communication with said second portion. The method involves causing a chemical modulation by moving retention alteration device relative to a modulator tube.

Abstract: A gas chromatographic system for analyzing gas components includes an analyzer, a constant temperature oven, an analyzer case, an indicator, an integrated sample conditioner, and a coupler. The analyzer includes a sample valve having a detector and a heater built therein and first and second columns wound around the periphery of the sample valve. The constant temperature oven accommodates the analyzer unit therein. The analyzer case accommodates the constant temperature oven. The indicator is protruded from the analyzer case to display analysis processes and results. The integrated sample conditioner provides an optimal condition for analysis. The coupler couples the analyzer unit with the sample conditioner so as to supply a sample gas and one of a carrier gas and a reference gas from the sample conditioner to the analyzer unit.

Abstract: A gas flow distribution system accumulates a sample from a sample bearing carrier gas in a micro-accumulator, delivers it using a carrier gas to a gas chromatography column, and supplies a carrier gas to the gas chromatography column to facilitate separation of the sample into sample components and transport the sample components to a mass spectrometer for trace vapor detection and analysis or testing in real time. The system is made of inert components and configured to have low dead volume for improved performance and accuracy of detection. External valves are employed for easy management and balance of the flow in the system to minimize operation time and facilitate continuous accumulation, delivery, and testing of the sample. The delivery of the sample to the gas chromatography column using an electrically heated cold trap as the micro-accumulator can be performed extremely fast.

Abstract: A gas chromatograph and method of chromatography are provided. Analytes, those compounds to be tested, are extracted from the sample by moving the sample into a column which has a stationary phase along the column walls. The column has two sections which are different in length. The longer section is heated and the analytes move to the shorter section. The longer section is then cooled and the entire column is heated. The device then functions as an analytical column and the analytes move out of the shorter section, through the longer section, and out of the column. A detector placed at the end of the column's longer section detects the presence of the compounds as they exit the column. In an alternate embodiment two separate columns are provided. One column is used as the extraction column and the other is used as the analytical column.

Abstract: Conventionally, the mass spectrometer unit is placed beside the gas chromatograph unit when the gas chromatograph unit is coupled with a mass spectrometer unit, whereas the normal detector is placed on the top of the gas chromatograph unit when it is coupled with a normal detector. This requires different structure of the gas chromatograph unit. In the gas chromatograph/mass spectrometer (GC/MS) system of the present invention that uses a suitably modified and re-designed mass spectrometer, the mass spectrometer unit is mounted on the top of the casing of the gas chromatograph unit. Thus a common gas chromatograph unit can be used whether it is coupled with a normal detector or with a mass spectrometer unit. Another advantage of the GC/MS system of the present invention is that it occupies less table-top or floor space.

Abstract: Gas chromatographs are disclosed that may be constructed to be portable, light, rugged, fast, sensitive, and to use only utilities (compressed gas and electricity) that are readily available in the field. The gas chromatographs can also perform novel extractions of analytes from gaseous, liquid, or solid samples. The chromatographs can be truly portable; they can operate with approximately 100 watts of power (at peak power consumption); and they are extremely fast. The chromatographs are not limited just to portable applications, but will also find many uses within laboratories, because they require minimal laboratory bench or other space, because they can operate at high speed, and because they can operate with minimal consumption of utilities (compressed gases, air conditioning, etc.).

Abstract: A water management system removes water vapor from the analyte slug that is desorbed from the trap. The water management system includes a device having a passage through which the volatile organic chemicals and water pass, the passage being designed to remove water vapor by swirling action on the stream. The amount of water removed is more than can be accounted for by simple condensation. The invention also includes the adjustment of the temperature of the water management device during the sample concentration cycle to prevent undesired condensation prior to desorption.

Abstract: A process is described for the separation of a mixture of substances by sorption of the mixture's components on two different sorption agents, which are individually and independently adjustable in their sorption properties, and is performed in a manner by which the mixture of substances to be separated is introduced into a separation chamber between the surfaces of the sorption agents, and in which the separation chamber is occupied by a gap medium, in which the mixture's components can be dissolved and/or dispersed and/or evaporated, while the phases containing the sorption agents move in opposing directions, and the separated components of the mixture held on the sorption agents are recovered after passage through the separation path. This process is characterized in that the separation chamber is formed by at least two or several hollow, concentrically superimposed cylindrical disks Z.sub.A and Z.sub.B, which are filled with structural elements, and which contain separation media Ph.sub.A and Ph.sub.

Abstract: A gas chromatograph system including a cold trap having two portions, a capillary tube and a porous layer open tubular (PLOT) column, for substantially simultaneously trapping lower and higher boiling point gasses. The capillary tube enables cold trapping of lower boiling point gasses while the PLOT column enables cold trapping of higher boiling point gasses. The capillary tube interconnects at one end to an analytical column and a sample gas source and interconnects at its other end to a first end of the PLOT column. The other end of the PLOT column interconnects to a carrier gas source and a vacuum source. The capillary tube and PLOT column are both positioned within a temperature controlled environment of the cold trap. During the collection mode, the temperature control device maintains a relatively low temperature to condense the sample components.

Abstract: Apparatus and method for on-line coupled liquid chromatography and gas chromatography analysis. The system includes a high-volume, liquid vaporizing chamber, or interface capillary tube which allows injection of a substantial volume of sample-carrying eluent and concentrates bands, obviating adverse effects on the resolution or peak shape of the components of interest. The vaporizing chamber is interposed between a packed or wall-coated open tubular capillary liquid chromatographic column and a capillary gas chromatographic column. The capillary liquid chromatographic column permits the use of small volumes of eluent and reduced flow rates.

Abstract: Gas chromatography systems which provide for high speed separation of polar compounds of interest from samples which also include non-polar compounds. Efficient separation is achieved through the use of a tandem series connected combination of analytical columns, one of which having a polar stationary phase material and another having a non-polar stationary phase material. In two embodiments of the invention the order of the analytical columns is reversed. Fluid flow conduits, valves and vents are provided in a manner which eliminates mechanical valves in a sample stream.

Abstract: A multidimensional gas chromatograph (GC) system having wide bore capillary and narrow bore capillary GC columns in series and having a novel system interface. Heart cuts from a high flow rate sample, separated by a wide bore GC column, are collected and directed to a narrow bore GC column with carrier gas injected at a lower flow compatible with a mass spectrometer. A bimodal six-way valve is connected with the wide bore GC column outlet and a bimodal four-way valve is connected with the narrow bore GC column inlet. A trapping and retaining circuit with a cold trap is connected with the six-way valve and a transfer circuit interconnects the two valves.

Abstract: A water management system removes water vapor from the analyte slug that is desorbed from the trap. The water management system includes a device having a passage through which the volatile organic chemicals and water pass, the passage being designed to remove water vapor by swirling action on the stream. The amount of water removed is more than can be accounted for by simple condensation. The invention also includes the adjustment of the temperature of the water management device during the sample concentration cycle to prevent undesired condensation prior to desorption.

Abstract: An improvement to a sample concentrator apparatus for extracting and concentrating trace organic components from an aqueous sample for subsequent analysis; and a method for concentrating trace organics.

Abstract: The invention is an apparatus and method for preparing volatiles collected from a sample for gas chromatographic analysis. Volatiles are collected from the sample in a volatile trap, such as a porous polymer trap. The volatile trap is then connected to a transfer line. The trap is heated to thermally desorb the volatiles, and an inert gas, such as helium, flows through the heated trap to transport volatiles through the transfer line into a capillary column located in a gas chromatograph oven. Inside of the oven, a portion of the capillary column is cooled with a cooling fluid such as liquid nitrogen to form a cold trap. When the cold trap is cooled, the desorbed volatiles are trapped in the cold trap. Then the cold trap is heated to allow the volatiles to be released and the volatiles are carried to the remainder of the capillary column for chromatographic analysis by an inert carrier gas.

Abstract: This invention relates to a chromatographic column with a separation column which is equipped on at least one side with an end threading mechanism for connecting a capillary, a precolumn, or another separation column, whereby the end threading mechanism has a support nut surrounding the column tube and a coupling nut, and the support nut is supported towards the corresponding end of the separation column at a stop part which is held in a recess at the separation column wherein the column has several axially consecutive recesses.

Abstract: An on-line supercritical fluid extraction multidimensional chromatographic system and method is described which provides a cell for extracting a target compound in a supercritical fluid, and a restrictor interface for trapping the extracted target compound while decompressing and venting the supercritical fluid. A pump and valve arrangement is provided to convey the trapped target compound through a micro LC column for separating (and detecting) constituents of interest from interfering species, and ultimately introducing constituent of interest into a gas chromatograph for analysis. The system is characterized as being "on-line" in that fluid communication is provided between all of the system components and the process is continuous. Similarly, the system is characterized as being "multidimensional" in that both liquid and gas chromatographic techniques can be employed in tandem to provide analysis, selectivity and sensitivity in the parts per billion range.

Abstract: A detachable column cartridge for a gas chromatograph is disclosed. The cartridge column contains analytical and reference columns, a heater and a thermocouple, and connects via detachable connectors to a base unit containing an injector, a detector and other components normally found in gas chromatographs. The cartridge arrangement permits a substitute column to be connected to the base unit easily, in the field, when different gases are to be separated and analyzed.

Abstract: A gas chromatography system in which prefocusing of a sample analyte is provided through the use of an adsorbent coated porous layer open tubular trap tube. Through the use of an adsorbent coated collection device low boiling point components can be successfully trapped for preconcentration and injection at temperatures well above that necessary when employing conventional cryo-focusing.

Abstract: A gas chromatography system featuring column bifurcation and pressure tuning. The system of this invention incorporates a bifurcated system in which samples eluting from a first separation column are directed selectively through one of two or more additional separation columns. Flow directing is achieved through the use of valves which switch carrier gas which are outside of the path of the analyte mixture. Effective tuning of the system is provided by adjusting the intermediate pressure which controls the effective lengths of the initial separation column and the additional final separation columns.

Abstract: A detachable column cartridge for a gas chromatograph is disclosed. The cartridge column contains analytical and reference columns, a heater and a thermocouple, and connects via detachable connectors to a base unit containing an injector, a detector and other components normally found in gas chromatographs. The cartridge arrangement permits a substitute column to be connected to the base unit easily, in the field, when different gases are to be separated and analyzed.