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: An integrated optical capillary electrophoresis system for analyzing an analyte. A modulated optical pump beam impinges on an capillary containing the analyte/buffer solution which is separated by electrophoresis. The thermally-induced change in the index of refraction of light in said electrophoresis capillary is monitored using an integrated micro-interferometer. The interferometer includes a first interferometer arm intersecting the electrophoresis capillary proximate the excitation beam and a second, reference interferometer arm. Changes in index of refraction in the analyte measured by interrogating the interferometer state using white light interferometry and a phase-generated carrier demodulation technique. Background thermo-optical activity in the buffer solution is cancelled by splitting the pump beam and exciting pure buffer solution in a second section of capillary where it crosses the reference arm of the interferometer.

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: 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 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 method of packing and unpacking a column chamber, comprising: a) packing a matrix material within a column chamber to form a packed column; and b) after the packing, unpacking the matrix material from the column chamber without moving the column chamber.

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: 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: An assembly for desorbing sampling tubes comprises a gas chromatograph known per se provided with an injector. The sampling tubes are provided with an inflow opening and an outflow opening. The assembly comprises an adapter which is placed in the injector and which is provided with a chamber which is bounded by a heat conducting housing. The adapter is arranged for placing a sampling tube in the chamber thereof, while in a condition of a sampling tube wherein it is placed in the adapter, the inflow opening thereof is in fluid communication with a first carrier gas supply duct, while the outflow opening of the sampling tube is in fluid communication via the injector with a gas chromatography column disposed in the gas chromatograph.

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: A method of measuring the effective temperature inside a sealed container having a headspace is provided. A liquid solvent is added to the container, and a solid compound is added to the liquid solvent to create a saturated solution. Vapor of the saturated solution is allowed to equilibrate in the headspace of the sealed container, and a volume thereof is transferred to a chromatographic column, where chromatographic readings of the equilibrated vapor are taken. A temperature within the sealed container is then calculated based upon the chromatographic readings of the equilibrated vapor, wherein the temperature calculation is based upon the concentrations of the liquid solvent and the solid compound in the equilibrated vapor.

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: An extraction device for liquid—liquid extraction of at least one analyte from a sample and on-line transfer of the analyte(s) to a gas chromatography extraction unit, a sample inlet, a sample outlet, and an organic liquid inlet, wherein the extraction device also includes a needle to be connected with a gas chromatography apparatus injector for the on-line transfer of the analyte(s) from the membrane-based extraction unit to the gas chromatography apparatus via the needle, an organic liquid being immobilized as a stagnant phase in a volume of less than 20 &mgr;l in the membrame-based extraction unit.

Abstract: Process for the production of a hydrofluoroalkane, according to which hydrofluoroalkane comprising organic impurities is subjected to at least two distillations.

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 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: An extraction device for liquid-liquid extraction of at least one analyte from a sample and on-line transfer of said analyte(s) to a gas chromatography extraction unit, a sample inlet, a sample outlet, and an organic liquid inlet, wherein it also comprises a needle to be connected with a gas chromatography apparatus injector for the on-line transfer of the analyte(s) from the membrane-based extraction unit to the gas chromatography apparatus via the needle, an organic liquid being immobilized as a stagnant phase in a volume of less than 20 &mgr;l in the membrame-based extraction unit.

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 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: An assembly for desorbing sampling tubes comprises a gas chromatograph known per se provided with an injector. The sampling tubes are provided with an inflow opening and an outflow opening. The assembly comprises an adapter which is placed in the injector and which is provided with a chamber which is bounded by a heat conducting housing. The adapter is arranged for placing a sampling tube in the chamber thereof, while in a condition of a sampling tube wherein it is placed in the adapter, the inflow opening thereof is in fluid communication with a first carrier gas supply duct, while the outflow opening of the sampling tube is in fluid communication via the injector with a gas chromatography column disposed in the gas chromatograph.

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: The invention concerns a method for the realignment of peaks in gas chromatographic analyses after the replacement of the used capillary column with a nominally equal one, wherein a K coefficient characteristic of the column is preventively calculated by flowing carrier gas in the column under stabilized conditions of pressure and flow rate and of the column temperature, said K coefficient being stored in a memory of the gas chromatographic system. Said K coefficient is used to correlate at least two of the above mentioned parameters in subsequent analyses, obtaining an automatic realignment of peaks. The invention also concerns the analytical equipment to perform the method, and the capillary gas chromatographic column characterized as reported above.

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.

Abstract: A chromatograph includes an inlet for receiving a sample and a pressurized hydrogen gas flow and in response providing a sample/fluid mixture; a separation column located in a temperature-controlled zone for receiving the sample/fluid mixture and for providing a column effluent stream; a detector for receiving the effluent stream and for providing a detector output stream; and a gas storage system for receiving the detector output stream (and optionally a split flow and a septum purge flow in the instance of a split/splitless inlet) and for storing the received gas stream for subsequent reuse. In the preferred embodiments of the gas storage system, a plurality of metal hydride storage (MHS) systems are used.

Abstract: An apparatus for removing fluorinated and chlorinated compounds contained in waste gas streams from semiconductor etch and deposition processes. The apparatus has a treatment chamber in which a plurality of liquid films are formed to absorb the fluorinated and chlorinated compounds contained in the waste gas streams that pass through the liquid films. The apparatus includes a tank for receiving the mixture of the absorbed fluorinated and chlorinated compounds and the liquid, and a dehumidifying device for stabilizing and dehumidifying the humidified waste gas streams.

Abstract: Chiral separations can be enhanced through the use of polymerized dipeptide-surfactant or oligopeptide-surfactant chiral micelles. Because polymerized micelles eliminate much of the complex dynamic behavior associated with conventional micelles, polymerized chiral micelles have stronger chiral recognition properties than do otherwise-identical, “conventional” or non-polymerized chiral micelles. Recovery of chiral ligands from polymerized chiral micelles is often easier, as the chiral ligands may typically be recovered by simple extraction with an appropriate organic solvent. By contrast, recovering the solute from a conventional, non-polymerized micellar medium by extraction with an organic solvent frequently results in the formation of troublesome emulsion systems. Polymerized chiral micelle systems are therefore beneficial in both preparative-scale and process-scale separations.

Abstract: Integrated analysis process and device for characterization of hydrocarbons in a petroleum product, in distillation fractions, by simulated distillation. The hydrocarbons of a petroleum sample are characterized without fractional distillation by coupling gas chromatography (GC) with liquid chromatography (LC) techniques. GC simulated distillation (SD) is carried out. The separation column is preceded by a precolumn of the same nature but shorter. At the outlet of the main column, retention means (CT, AC) allow to collect and to store one or more light fractions that are sent each to a GC analytical column (6) allowing detailed analysis of the hydrocarbons, and one or more middle fractions. The remaining heavy fraction is collected at the precolumn outlet. The middle and heavy fractions are characterized by a combined LC-GC chromatography unit. Several interfaces allowing GC-GC-LC-GC coupling are described.

Abstract: A system for analysis of vapor constituents in a gaseous and/or liquid media includes an analyzing gas chromatographic unit, an in-line preconcentrator assembly having a trap housing, an adsorbent material received in the trap housing, and a transfer line unit couplable to the trap housing and directly connected to the analyzing unit. Carrier mechanism drives the trap housing with respect to the transfer line unit linearly or along an arc trajectory. When the trap housing is displaced from the transfer line unit, the media surrounding the trap housing is forced inside of the trap housing by a pump and vapor constituents are adsorbed on the adsorbent material within the trap housing. When the trap housing is moved in pressure tight engagement with the transfer line unit, the adsorbent material is heated to release the vapor constituents from the adsorbent material.

Abstract: A method for identifying components within a known type of sample through pattern recognition between an array of recognition coefficients generated from the attributes and stable relationships of a plurality of peaks within a chromatogram of a sample to be analyzed and a similar array of recognition coefficients generated from the attributes and stable relationships of a plurality of peaks from a set of one or more historical chromatograms of the known type of sample. The group of attributes include, but are not limited to: retention time, peak shape including symmetry, width and duration, peak size including area and height, and algorithmic measures of peak type.

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

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

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

Abstract: A method for determining the efficiency of a carbon filter used to absorb hydrocarbons from organic solvents. A sample of the solution, used to remove CO.sub.2 and H.sub.2 S from natural hydrocarbon gases, is taken after it has passed through the carbon filter. A solution of an internal standard and carbon disulfide is added to the sample to concentrate the hydrocarbons into the solution. A second sample taken from the solution containing the concentrated hydrocarbons and is passed through a gas chromatograph which has a fast temperature ramp to measure the peak areas of the hydrocarbons and the internal standard. The concentration of the measured hydrocarbons are determined by comparing the peak area counts against that of the internal standard.

Abstract: A method for identifying analytes of interest by referencing to a retention factor database corresponding to a plurality of identified analytes that is independent of column dimensions and carrier gas type while dependent upon stationary phase type ratio and a relative temperature program. The retention factor database is generated on a reference GC system in which the column head pressure is adjusted to ensure high reproducibility of retention times by locking the column void time and/or the retention time of an identified analyte to a specific value such that accurate retention factors (k) can be calculated in accordance with the formula: ##EQU1## where VT is the void time of the column having a specified stationary phase and phase coating installed in a GC system operating in accordance to a specified temperature program (where time is expressed in units of column void time).

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 method of packing and unpacking a column chamber, comprising: a) packing a matrix material within a column chamber to form a packed column; and b) after the packing, unpacking the matrix material from the column chamber without moving the column chamber.

Abstract: The present invention provides an improved method for calculating and adjusting the column head pressure of a GC instrument based on the column's plate capacity, N.sub.c, and film thickness, d.sub.s, measured ideally during the manufacturing process and identified with the column such that software associated with the GC instrument can calculate a new column head pressure based on the relationship between the plate capacity and film thickness of the existing column to the plate capacity and film thickness of the new or shortened column. The column head pressure of the GC is adjusted to the new column head pressure to provide a reduction in the column-to-column non-reproducibility error in retention times of all peaks.

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: A chromatography column for microwave heating either incorporates microwave absorbing material into the column itself or positions the column adjacent to microwave absorbing material so that the column and the chromatography sample contained therein are heated by the microwave absorbing material via conduction or convection. For example, a microwave absorbing material (e.g., ferrite) can be fused into the inner silica layer or incorporated in an outer polymer layer of the column. Microwave absorbing material can also be incorporated into an external element (e.g., an outer tube, sleeve, or spool) positioned adjacent to the chromatography column. A layer of thermal insulation can be placed around the column to decrease the rate of heat loss. Optionally, a gap can be provided between the chromatography column and thermal insulation to further reduce heat loss during the heating cycle and to accelerate cooling at the end of the heating cycle by making it possible to ventilate the heated column.

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

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

Abstract: A primary chromatographic system is operated with a standard sample at several temperatures to generate primary retention times which are fitted to a function to determine thermodynamic constants to relate the times to temperature. A target chromatographic system is operated with the standard sample to generate secondary retention times. The function is used with these times to determine and an effective column parameter for the target system. The function then is used with this parameter and the primary times to determine a pressure program. Further operation of the target system with a application sample and the pressure program effects standardized retention times. A particular searching technique is utilized to apply the function. A temperature calibration technique with a selected sample measures column temperature for the target system, and a validation is done on the target system.

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

Abstract: Energy efficiency of a thermal zone in an analytical instrument is improved by use of an oven cavity insert that may be removably positioned in an insulated enclosure in an oven cavity housing, whereby the combination of the oven cavity insert and one or more of the enclosure walls completely encloses a first space suitable for effecting the thermal zone. The oven cavity insert is positionable so as to separate the first space from at least a portion of the unused volume of the oven cavity, thus reducing the volume of the thermal zone, so as to reduce the amount of heating or cooling required for temperature control of a component positioned therein. When present in the oven cavity, the contemplated oven cavity insert effectively conceals a portion of the housing from the thermal zone, thus reducing the effective thermal mass of the oven cavity housing.

Abstract: Screening an unknown sample for a plurality of known or "target" analytes may be accomplished by creating and searching a retention time-locked spectral database for the entire chromatographic output of a locked GC system locked to such spectral database. Identification of target analytes having for example, known significant mass spectral ions and mass ion ratios corresponding to known analytes of interest believed to be found within a pre-defined retention time window is improved by direct comparison of significant mass spectral ions and the mass ion ratios within a specified retention time window.

Abstract: A chromatography column for microwave heating either incorporates microwave absorbing material into the column itself or positions the column adjacent to microwave absorbing material so that the column and the chromatography sample contained therein are heated by the microwave absorbing material via conduction or convection. For example, a microwave absorbing material (e.g., ferrite) can be fused into the inner silica layer or incorporated in an outer polymer layer of the column. Microwave absorbing material can also be incorporated into an external element (e.g., an outer tube, sleeve, or spool) positioned adjacent to the chromatography column. A layer of thermal insulation can be placed around the column to decrease the rate of heat loss. Optionally, a gap can be provided between the chromatography column and thermal insulation to further reduce heat loss during the heating cycle and to accelerate cooling at the end of the heating cycle by making it possible to ventilate the heated column.

Abstract: An apparatus for the recognition of exchangeable parts in an analytical measuring instrument or in an analytical measurement system with several analytical devices, which contain exchangeable parts has identification modules each attached to an exchangeable part, and transmit-receive devices which can receive information signals from an identification module and send information signals to an identification module, and a control device which evaluates the information from an identification module. The control device can cause a message to be displayed on a display device, if the information read out from an identification module does not fulfill certain conditions, for example with regard to the quality of the corresponding part.

Abstract: Device for connecting a first duct of a very small diameter, such as for instance a needle or a capillary column, to a second duct, wherein the device comprises a receiving part and a sealing element, wherein the receiving part is provided with a duct bore in which the first duct is slidably receivable, wherein the receiving part is also provided with a sealing-element bore which intersects the duct bore and in which the sealing element is slidably received, wherein the sealing element is provided with a recess, wherein the sealing element is adapted to assume a sealing position in which the duct bore is sealed, and is adapted to assume a connecting position in which the two duct bore parts on either side of the sealing-element bore are in fluid connection with each other via the recess, wherein the sealing element is biased in the sealing position by a spring under spring action.

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

Abstract: A method of admitting and receiving a sample into a gas chromatographic column is provided in which a step increase in pressure is performed in combination with the application of a negative axial thermal gradient to provide pre-separation of solutes in the sample within the inlet region of the column. The method includes the steps of introducing a sample into the column at a first pressure and temperature, rapidly raising the temperature to invoke a negative axial thermal gradient, and then substantially instantaneously increasing the pressure. The method causes the solutes in the sample to be partially separated into narrow zones within the inlet region, resulting in eventually achieving maximum resolution.