Thermochemical detector for gas chromatography

FIELD: physics.

SUBSTANCE: thermochemical detector comprises operating and comparative sensitive elements in the form of platinum filaments, one of which - the operating sensitive element - is coated with a thin layer of an oxidation process catalyst. The operating and comparative platinum filaments are placed in one cylindrical housing in which two diametrically lying holes are drilled for a gas stream; one of the holes is intended for inserting a capillary which feeds eluate from a column opposite the electric lead with a welded middle point of series-connected platinum filaments, which are connected in a bridge measuring circuit. The eluate-feeding capillary is provided with two baffles arranged in parallel to the platinum filaments, and has a special cross-sectional shape for uniform distribution of the gas stream from the column to the platinum filaments, and the feed capillary is sealed in the cylindrical housing with an inorganic silicate adhesive.

EFFECT: high sensitivity and precision of detection.

1 dwg, 2 tbl

 



 

Same patents:

FIELD: gas chromatographic devices; chemical industry; oil industry; metallurgy; medicine; biology etc.

SUBSTANCE: detector can be used in gas chromatographic device as with filled and empty capillaries and micro-nozzle separating columns for analyzing complex mixtures of matters having as natural and artificial origin. Detector has heater made in form of metal thread, two film thermo-sensitive elements mounted in gas channel at output of chromatographic column in parallel to the heater at similar distance. Thermo-sensitive elements are connected into opposite arms of bridge circuit. Electric current source for the heater has automatic controller to keep temperature and resistance of the source to permanent value.

EFFECT: improved precision of detection; improved sensitivity.

2 dwg

The invention relates to gas chromatography and can be used for qualitative and quantitative analysis not identified components of complex mixtures of substances belonging to different classes of organic compounds

The invention relates to the field of analytical techniques, namely, devices for measuring gas flow in capillary gas chromatography

FIELD: gas chromatographic devices; chemical industry; oil industry; metallurgy; medicine; biology etc.

SUBSTANCE: detector can be used in gas chromatographic device as with filled and empty capillaries and micro-nozzle separating columns for analyzing complex mixtures of matters having as natural and artificial origin. Detector has heater made in form of metal thread, two film thermo-sensitive elements mounted in gas channel at output of chromatographic column in parallel to the heater at similar distance. Thermo-sensitive elements are connected into opposite arms of bridge circuit. Electric current source for the heater has automatic controller to keep temperature and resistance of the source to permanent value.

EFFECT: improved precision of detection; improved sensitivity.

2 dwg

FIELD: physics.

SUBSTANCE: thermochemical detector comprises operating and comparative sensitive elements in the form of platinum filaments, one of which - the operating sensitive element - is coated with a thin layer of an oxidation process catalyst. The operating and comparative platinum filaments are placed in one cylindrical housing in which two diametrically lying holes are drilled for a gas stream; one of the holes is intended for inserting a capillary which feeds eluate from a column opposite the electric lead with a welded middle point of series-connected platinum filaments, which are connected in a bridge measuring circuit. The eluate-feeding capillary is provided with two baffles arranged in parallel to the platinum filaments, and has a special cross-sectional shape for uniform distribution of the gas stream from the column to the platinum filaments, and the feed capillary is sealed in the cylindrical housing with an inorganic silicate adhesive.

EFFECT: high sensitivity and precision of detection.

1 dwg, 2 tbl

FIELD: fire safety.

SUBSTANCE: method for determining component concentration in a two-component gas mixture placed in a measuring chamber based on the use of the thermal conductivity of a controlled gas mixture, at first the mass m of the controlled component id calculated in the gas mixture according to the formula m=ρ vccm1cm2cm12)/λcm2, where ρis the density of the controlled component, vc is the volume of the chamber, λcm1 is the thermal conductivity of the first component, λcm2 is the thermal conductivity of the second controlled component, λcm12 is the thermal conductivity of the gas mixture. Then, taking into account the mass of one molecule of the second controlled component, the concentration of the required parameter is determined.

EFFECT: increased accuracy of measuring the concentration of a component in a two-component gas mixture.

1 dwg

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