Automatic thermal desorption instrument based on thermal gas desorption

Abstract

The invention relates to an automatic thermal desorption instrument based on thermal gas desorption. The auotomatic thermal desorption instrument comprises a sample pipe provided with a first desorption sample outlet and a condensing adsorption pipe which is provided with a desorption sample inlet, an adsorption / desorption inlet / outlet and a second desorption sample outlet and is filled with adsorbent, wherein a first end of a first sample output pipe is communicated with the desorption sample outlets, and a second end of the first sample output pipe extends out of the end surface of the adsorbent after penetrating through the condensing adsorption tube and the adsorbent; a first end of a second sample output pipe is communicated with the second desorption sample outlet; a preheated carrier gas conveyer pipe the first end of which is communicated with the adsorption / desorption inlet / outlet is provided with a heater, and a second end of the preheated carrier gas conveyer pipe is provided with a first control valve; a desorption exhaust pipe connected with the first control valve is provided with a second control valve; and a second carrier gas conveyer pipe is connected with the first control valve. Besides, the desorption instrument also comprises a first carrier gas conveyer pipe, a transfer pipe the first end of which is communicated with a gas chromatograph and a changeover valve. By adopting the invention, the secondary desorption rate can be improved, the chromatographic peak is sharpened and simultaneously the desorption efficiency is improved.

Description

Technical field: [0001] The invention relates to a sample pretreatment device for an analysis instrument, in particular to an automatic thermal desorption and desorption instrument using hot gas desorption. Background technique: [0002] As a sample pretreatment unit of an analytical instrument, primary thermal desorption (thermal desorption is also called thermal desorption) is to desorb the prepared sample tube directly to the gas chromatograph for analysis after heating. Generally relatively large (the industry standard is 1 / 4 of the outer diameter of the tube) will cause excessive broadening of the chromatographic peaks. [0003] The traditional two-stage desorption is to desorb the sample tube into the low-temperature condensation adsorption tube, and then quickly heat the condensation adsorption tube, and the vaporized sample is blown back to the gas chromatograph by the carrier gas. The rate of temperature rise in the condensation adsorption tube directly affects the...

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Problems solved by technology

Since the carrier gas is flowing, it will continuously take away heat, its real temperature is lower than the temperature indicated by the heater on the condensation adsorption tube, and the speed of heat transferred to it by the condensation adsorption tube is affected by the size of the condensation adsorption tube, Influenced by factors such as material, carrier gas type, flow rate, etc., this will bring about the broadening of component chromatographic peaks

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