Nozzle assembly for micro-size hydrogen flame ionization detector

Abstract

The invention provides a nozzle assembly for a micro-size hydrogen flame ionization detector ([mu]-FID). The nozzle assembly is composed of a nozzle, a lead tube, an upper clamp sleeve, a sleeve tube, a lower clamp sleeve, a detector body and a screw cap. When the screw cap is upwardly screwed tightly, a truncated conical sealing surface of a second groove in a hole in the detector body and an inverted truncated conical sealing surface of the screw cap press the truncated conical sealing surfaces at the tops of the two clamp sleeves respectively from up and down, and meanwhile, the metal sleeve between the two clamp sleeves presses the bottom surfaces of the two clamp sleeves, so that the truncated conical sealing surface of the upper clamp sleeve can seal an upper channel, and the truncated conical sealing surface of the lower clamp sleeve can seal a lower channel (in which hydrogen is fed). The nozzle assembly has the advantages that the sealed mechanical structure is simple, compact and reliable, the assembly is short in length and size of the [mu]-FID is reduced, dead volume in a combustion chamber is reduced, air flow is more stable, and the noise of the [mu]-FID is lower and the nozzle assembly is easy to replace.

Description

technical field [0001] The invention relates to the technical field of hydrogen flame ionization detectors, in particular to a nozzle assembly of a miniature hydrogen flame ionization detector. Background technique [0002] Hydrogen Flame Ionization Detector (FID) is the most widely used detector in gas chromatography. This type of detector uses hydrogen flame as ionization source to ionize the measured substance, and the micro current generated is amplified for detection. The outstanding advantage of FID is that it responds to almost all organic substances, especially to hydrocarbon compounds with high sensitivity (ppb level), and the response value is proportional to the number of carbon atoms; it is not sensitive to inorganic substances; gas flow rate, pressure and temperature and other operations Changes in conditions have little effect on its response; the linear range of FID is 6-7 orders of magnitude, the time constant of the detector itself is between 2-5ms, the dead...

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Problems solved by technology

[0004] In order to improve the deficiencies of the prior art, the present invention provides a new type of nozzle assembly for a miniature hydrogen flame ionization detector, which effectively solves the problems of the existing μ-FID sealing mechanical structure and long nozzle assembly, and at the same time Also improves reliability in the detector nozzle area

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