Abstract: A gas analysis system and method use foreground broadband gas monitoring and background selective gas analysis. The foreground broadband monitoring indicates concentrations of a class of chemicals or contaminants in a gas sample, provides real-time warnings of contaminants, and can activate the background selective analysis. Separate broadband detectors and gas analyzers can respectively perform broadband monitoring and selective analysis. To reduce system components, a broadband detector that performs broadband monitoring switches to measure concentrations of chemicals output from a separation device for the selective analysis.

Abstract: A system for concentrating a volatile organic compound (VOC) sample uses in one embodiment a bypass line and a valve coupled thereto to regulate an amount of carrier gas flowing through a carrier gas line. A flow splitter fluidly couples the bypass line to the carrier gas line, and connects to the output of a cryofocuser. The valve opens at the onset of transferring the VOC sample from a concentrator trap such as a sorbent trap to the cryofocuser, thereby resulting in an increased amount of carrier gas flow between the concentrator trap and the cryofocuser for more efficient desorbing of the concentrator trap. The valve is closed when the focused VOC sample is flushed out of the cryofocuser for delivery to a gas chromatograph, preferably delivering the entire VOC sample to the GC.

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: 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 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 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: 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 inlet system is used in conjunction with a standard gas chromatograph/mass spectrometer to facilitate the analysis of volatile components of substances fired from inkjet pens. The system allows for the investigation of changes in the ink resulting from resistor firing. In addition, the system can be used as a diagnostic tool to detect failures in individual firing chambers. After a block is cooled with liquid nitrogen, an analyte sample of ink is deposited on a stage in a chamber in the block and the chamber is then sealed. The stage is then heated vaporizing a portion of the analyte sample. A transfer gas passes over the stage and mixes with vaporized analyte. The mixture then enters a gas chromatograph/mass spectrometer which determines the analyte sample's components and relative amounts thereof.

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: An apparatus and method for separating and analyzing a component of a fluid sample that is considered to be a contaminant, and particularly, that is or may be an organic material. The invention is predicated on the introduction of the sample fluid in a pulsed manner via a first carrier fluid into a feed chamber. A membrane is located between the feed chamber and an exit chamber, and in fluid registry therewith. When the sample enters the feed chamber, the component to be separated and analyzed can permeate the membrane, and thus passes through the membrane to the exit chamber, and then enters a second carrier fluid which carries it to a detector for analysis. The detector may be a gas chromatograph (GC), mass spectrometer (MS) or the like.

Abstract: A chromatographic oven assembly is described. The assembly includes an oven which is machined or formed from a low thermal mass material such as a silica/ceramic composite to form a cylindrical oven cavity. The capillary column is supported in a helical configuration in the oven cavity spaced from the walls with the ends extending through the insulating material for introduction of sample mixture and detection of the separated components of the mixture. An electric heater and a fan are mounted in a separate module and introduce heated air through a tangential opening, and receive air after it has circulated in the oven through a tangential opening. Air is continuously heated and circulated to maintain the column at the elevated temperature. For cooling, the heater is bypassed and cool ambient air is introduced tangentially into the oven by the fan and expelled to the atmosphere. In another embodiment, the fan and heater are mounted in the oven cavity.

Abstract: Problem:

Abstract: A method applies retention-time locking to multidimensional gas chromatography. Retention time locking is applied to both standard and comprehensive multidimensional gas chromatography. Retention time locking may be applied to either or both of the columns in a multidimensional gas chromatography system. Additionally, if the multidimensional system contains more than two columns in series, retention time locking can be applied to any or all of the columns as required.

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: A method applies retention-time locking to the retention times and/or the column(s) void times of a target analyte(s) being eluted thru a multidimensional gas chromatography system. Retention time locking is applied to both standard and comprehensive multidimensional gas chromatography via the steps of adjusting column(s) head pressure in a locking multidimensional gas chromatograph system such that the measured retention times and/or void times match the known accepted. Retention time locking may be applied to either or both of the columns in a multidimensional gas chromatography system. Additionally, if the multidimensional system contains more than two columns in series, retention time locking can be applied to any or all of the columns as required.

Abstract: Inverse gas-chromatography apparatus for investigating the properties of a solid material, having a carrier fluid, comprising at least two fluid components (typically water and an inert gas); a second flow comprising the carrier fluid components and probe material; a temperature controlled column, for holding the solid material; a switch for selectively passing the flow of carrier fluid and the second fluid flow through the column; a detector for detecting the passage of the probe material through the column. The relative proportions of the fluid components in the flow of carrier fluid and the second fluid flow can be controlled.

Abstract: A thermostat array including an array of two or more capillary columns (10) or two or more channels in a microfabricated device is disclosed. A heat conductive material (12) surrounded each individual column or channel in array, each individual column or channel being thermally insulated from every other individual column or channel. One or more independently controlled heating or cooling elements (14) is positioned adjacent to individual columns or channels within the heat conductive material, each heating or cooling element being connected to a source of heating or cooling, and one or more independently controlled temperature sensing elements (16) is positioned adjacent to the individual columns or channels within the heat conductive material. Each temperature sensing element is connected to a temperature controller.

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: 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 highly sensitive electronic ion cell for the measurement of trace elements in He carrier gas which involves glow discharge. A constant wave (CW) glow discharge detector which is controlled through a biased resistor, can detect the change of electron density caused by impurities in the He carrier gas by many orders of magnitude larger than that caused by direct ionization or electron capture. The glow discharge detector utilizes a floating pseudo-electrode to form a probe in or near the plasma. By using this probe, the large variation of electron density due to trace amounts of impurities can be directly measured.

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: There is provided a gas analyzing apparatus capable of minimizing gas remaining by integrating gas switching apparatuses into one and capable of analyzing impurities of ppb level to sub-ppb level contained in various kinds of high-purity gases efficiently and accurately.

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: An analyzing apparatus for assaying various kinds of trace impurity contents in various kinds of high-purity gases, having an atmospheric pressure ionization mass spectrometer useful for determination of trace impurity contents in such high-purity gases on the ppb to sub ppb levels and a gas chromatograph integrated therewith, enabling high efficiency determination of trace impurity contents in high-purity gases. The analyzing apparatus having a gas chromatograph (8) and an atmospheric pressure ionization mass spectrometer (6), is provided with a system (10) for introducing a sample gas introduced from a sample gas introduction source directly to the atmospheric pressure ionization mass spectrometer (6); a system (14a, 14b) for introducing the sample gas via the gas chromatograph (8) to the atmospheric pressure ionization mass spectrometer (6); and a channel selector (11, 13, 15) for changing over the channel of the sample gas to either of these two systems.

Abstract: A chromatogram analyzer is provided which analyzes a chromatogram obtained by applying a sample containing an analyte. The chromatogram analyzer can be used after peak detection, for example, based on predicted peak emergence times for respective analytes of interest and can determine proper baselines even in the presence of peaks attributable to components other than the analytes or ghost peaks. The chromatogram analyzer is used for an analysis of a chromatogram developed by chromatography, namely by separating and detecting analytes in a sample. Although chromatography is divided into various types of liquid chromatography and gas chromatography according to the principles for separation and development, a chromatogram obtained by any type of chromatography can be analyzed. For example, an electrophoretically obtained result stained with a proper dye can be analyzed by using the present invention after photometric scanning.

Abstract: A headspace sampling apparatus collects headspace vapor from a container holding a vapor phase and a non-vapor phase of a substance which is to be analyzed. The apparatus includes a dual needle apparatus (55). The dual needle apparatus is extended through a septum into a headspace portion (57) of a vial (58) holding the substance for analysis. A purge gas is supplied to a first fluid passage (54) in the dual needle. The purge gas sweeps the material in the headspace and passes the sample through a send fluid passage (56) in the needle. The extracted sample is selectively directed through a six port valve (76). In a first condition of the valve the sample is directed to a trap (80) for collection therein. After sample collection the condition of the six port valve is changed. Material is desorbed from the trap and directed through the valve into an analytical instrument (82).

Abstract: This invention concerns a method, a device, and an apparatus to detect changes of state in a capillary tube, in particular a gas-chromatographic column or pre-column and to consequently control the conditions under which samples are injected or introduced. The detection is carried out through changes in the temperature of the capillary tube, and/or changes in pressure, or flow rate of the carrier gas. The invention further concerns a method to control gas-chromatography functions by means of a specially designed software, based on the above-mentioned detections on a sample apparatus.

Abstract: A system for determining the energy and volume delivered by a flowing natural gas carried within a pipeline based on BTU content analysis of the natural gas using a micro-miniature gas chromatograph. By monitoring key parameters of the flowing natural gas, such as temperature, pressure, flow rate, and BTU content, the system 110 accurately determines the total energy and total volume delivered by the flowing natural gas over a programmable duration of time. Micro-miniature fabrication of the gas chromatograph imparts important advantages to the system 110, including small size, modular design, low power consumption, fast BTU analysis times, and low consumption of consumable carrier and reference gases.

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 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 highly sensitive electronic ion cell for the measurement of trace elements in He carrier gas which involves glow discharge. A constant wave (CW) stable glow discharge detector which is controlled through a biased resistor, can detect the change of electron density caused by impurities in the He carrier gas by many orders of magnitude larger than that caused by direct ionization or electron capture. The stable glow discharge detector utilizes a floating pseudo-electrode to form a probe in or near the plasma and a solid rod electrode. By using this probe, the large variation of electron density due to trace amounts of impurities can be directly measured. The solid rod electrode provides greater stability and thus easier alignment.

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: In an arrangement for producing a directional and cooled gas jet in an ion source with a gas inlet or a UV/fluorescence detection cell including a gas inlet, wherein a capillary extends with one end into the interior of the ion source which is evacuated, the one end is provided with a nozzle for discharging a gas sample into the ion source while being subjected to adiabatic cooling and the width of the nozzle opening is at most 40% of the inner diameter of the capillary and the capillary is heatable for preventing condensation of gas sample components in the nozzle.

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.

Abstract: In a process for determining the number of components involved in the formation of peaks, bands, and signals which are obtained in spectrograms where energy-correlated measurement values, such as extinctions, increase and decrease as a function of an evolving parameter, such as time, four different measurement values with at least three evolving parameter values are determined, three differences are formed from the four energy-correlated measurement values on the basis of the same evolving parameter, two quotients are formed from the respective differences and the two quotients are plotted over one another in a diagram, whereby a point is obtained if one component is responsible, a straight line is formed if two components are responsible and a curve is formed if more than two components are responsible for the formation of the peaks, bands, or signals.

Abstract: A gas chromatograph has a pressure sensor measuring a pressure in a sample introduction part, a flow control valve controlling carrier gas flow rate, a flow sensor measuring a flow rate of the carrier gas, a split flow path exhausting part of a carrier gas and sample from the introduction part, an exhaust valve placed in the sprit flow path, and a monitor screen. The controller controls the flow control valve to flow the carrier gas at the designated flow rate into the introduction part, reads an output of the pressure sensor after making the exhaust valve fully open, calculates a flow path resistance of the filter by using an output of the pressure sensor and a flow path resistance of the chromatographic column, and controls the monitor screen to display an indication for exchanging the filter when the calculated resistance reaches the preset value corresponding to a state in which the filter is stuffed.

Abstract: An ultratrace detector system for hand-held gas chromatography having high sensitivity, for example, to emissions generated during production of weapons, biological compounds, drugs, etc. The detector system is insensitive to water, air, helium, argon, oxygen, and CO2. The detector system is basically composed of a hand-held capillary gas chromatography (GC), an insulated heated redox-chamber, a detection chamber, and a vapor trap. For example, the detector system may use gas phase redox reactions and spectral absorption of mercury vapor. The gas chromatograph initially separates compounds that percolate through a bed of heated mercuric oxide (HgO) in a silica—or other metal—aerogel material which acts as an insulator.

Abstract: A microwave heating apparatus is used for heating a chromatographic column assembly containing a microwave absorbing material. The microwave heating apparatus includes an antenna transmitting a microwave signal and a resonant cavity containing the chromatographic column assembly. The chromatographic column assembly extends relative to predetermined electromagnetic field strength contours within the resonant cavity to provide a predetermined heating profile along the length of the chromatographic column assembly. For example, a single-mode chromatographic column microwave oven can be used to heat a coiled chromatography column to a desired temperature gradient along its length. Oven design embodiments utilizing coaxial transmission line structures, coaxial resonators, and cylindrical resonators are described. Oven designs are provided to achieve more suitable oven size for fixed operating frequencies. Apparatuses for impedance matching an oven to a microwave source are described.

Abstract: A flow of a carrier gas through a column is provided. A sample is provided in the column, and a temperature of a longitudinally short portion of the column is raised to a predetermined controlled high temperature at which volatile substances are released from the sample packing and are carried by the carrier gas. The column is cooled on each side of the short portion to a low temperature at which the volatile substances condense or adsorb on the column packing. By continuously moving the heated short portion from an inlet end to an outlet end of the packing in a direction of carrier gas flow the volatile substances selected by the controlled high temperature are released. Four particularly useful and advantageous applications can be identified for the invention. Firstly, it provides an improved gas chromatograph (GC) injector. Secondly, it provides an improved thermal separator or extractor.

Abstract: A gas analyzer for an oil drilling rig normally flows gas captured from a mud pit source through parallel paths from the gas source to a total gas analyzer. One of the paths is a loop path. Periodically the loop path is switched from the source to the total gas analyzer and connected to a path from an air supply to a chromatograph. After a short time during which the gas from the loop path is transferred to the chromatograph then the loop path is switched back to the original parallel path. This arrangement permits a small instrument to perform both the functions of total gas analyzer and chromatograph.

Abstract: Disclosed is a method for taking the data generated from an array of responses from a multichannel instrument, and determining the characteristics of a chemical in the sample without the necessity of calibrating or training the instrument with known samples containing the same chemical. The characteristics determined by the method are then used to classify and identify the chemical in the sample. The method can also be used to quantify the concentration of the chemical in the sample.

Abstract: A gas chromatographic device has an inlet system, a column and a pressure reducing means combined and assembled in such a series arrangement that provides adequate system performance with shorter wide bore column length and shorter sample analysis times needed during a peak integration and evaluation process performed by a connected mass spectrometer system. Pressure reducing means may be integral part of the inlet system or the column when positioned between the inlet system and the column. Pressure reducing means preferably positioned before the column and being capable of reducing the pressure prevailing at the inlet of said pressure reducing means to a column outlet pressure which is essentially vacuum. Preferably, the inlet pressure of the device is in a range between 10 kPa and 1000 kPa and the absolute pressure prevailing at the outlet of said pressure reducing means is in a range between 0.00001 kPa and 50 kPa.

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 microwave heating apparatus is used for heating a chromatographic column assembly containing a microwave absorbing material. The microwave heating apparatus includes an antenna transmitting a microwave signal and a resonant cavity containing the chromatographic column assembly. The chromatographic column assembly extends relative to predetermined electromagnetic field strength contours within the resonant cavity to provide a predetermined heating profile along the length of the chromatographic column assembly. For example, a single-mode chromatographic column microwave oven can be used to heat a coiled chromatography column to a desired temperature gradient along its length. Oven design embodiments utilizing coaxial transmission line structures, coaxial resonators, and cylindrical resonators are described. Oven designs are provided to achieve more suitable oven size for fixed operating frequencies. Apparatuses for impedance matching an oven to a microwave source are described.

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 silicon-based carrier matrix having a high ratio of surface area to volume is intended for use in integrated microanalysis systems. The carrier matrix comprises at least one layer of microporous silicon on a body of monocrystalline silicon. A method for producing the carrier matrix comprises electrochemical etching of a body of monocrystalline silicon, thereby to form at least one layer of microporous silicon on this body. The use of the carrier matrix for chemical sensors in integrated microanalysis systems, as well as in various sorts of chromatography, is also disclosed.