Adsorption and analysis device of headspace sample

Abstract

The invention relates to an adsorption and analysis device of a headspace sample, comprising double needles, a first air carrying pipeline, a first connecting pipeline, an adsorption pipe, a second connecting pipeline, an adsorption and analysis pipeline, a second air carrying pipeline, a third air carrying pipeline, an exhaust pipeline and a transmission pipeline. One end of the double needles is inserted into a sample bottle, and the double needles comprise a carrying air inlet hole and an air outlet hole; the first air carrying pipeline is communicated with the carrying air inlet hole; the first end of the first connecting pipeline is communicated with the air outlet hole; the adsorption pipe comprises an inlet, an outlet and an adsorption and analysis inlet-outlet and is filled with adsorbent; the second connecting pipeline is communicated with the outlet of the adsorption pipe; the adsorption and analysis pipeline, the second air carrying pipeline, the third air carrying pipeline and the exhaust pipeline are communicated with the adsorption and analysis inlet-outlet; the transmission pipeline is connected with a gas chromatograph; the second end of the first connecting pipeline penetrates through the inlet of the adsorption pipeline and the adsorbent to extend out of the end surface of the adsorbent; switching valves are arranged among the second connecting pipeline, the exhaust pipeline, the second air carrying pipeline and the transmission pipeline; and a first control valve and a second control valve are arranged between the third air carrying pipeline and the adsorption and analysis pipeline. The invention simultaneously has the headspace and purging and trapping functions,shortens time for extracting and analyzing a sample and can obtain lower detection limit and high sensitivity.

Description

Technical field: [0001] The invention relates to a sample pretreatment device of an analytical instrument, in particular to a headspace sample adsorption analysis device. Background technique: [0002] Headspace analysis is to put the sample liquid or solid into a closed container, and the sample and the gas above it form an equilibrium. Based on a basic physical law, the inherent volatile compounds in the sample will appear in its gaseous form. above. The relative concentrations between the two phases will depend on the partial pressures of these compounds at the time. It only needs to extract a part of gas phase substances to analyze volatile organic compounds without the interference of non-volatile substances. This is the headspace analysis method. It is the development requirement and trend of modern analytical instruments to be able to quickly and accurately extract samples and send them to a gas chromatograph for detection, and the detection of low levels of organic...

AI Technical Summary

Problems solved by technology

The headspace sample gas is directly extracted and sent to the gas chromatograph to obtain very good reproducibility. Because there is no concentration, the extraction time and analysis time of the sample are much shorter. The disadvantage is that the minimum detection limit is not as good as the concentrated extraction. ; while the concentrated extraction can obtain lower detection limits and high sensitivity, the corresponding time of the extraction that needs to be concentrated will be longer, and the reproducibility of the analysis results will be worse

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