Sampling analysis device and sampling analysis method for atmosphere volatile organic compounds

Abstract

The invention discloses a sampling analysis device for atmosphere volatile organic compounds. The sampling analysis device comprises a low-temperature environmental box and an atmosphere sampler, wherein low-temperature cold trap devices are arranged in the low-temperature environmental box and comprise a first cold trap, a second cold trap and a third cold trap, the first cold trap comprises a first condensation pipe and a first semiconductor chilling plate set, and a first heating wire is wound on the first condensation pipe; the second cold trap comprises a second condensation pipe and a second semiconductor chilling plate set, and a second heating wire is wound on the second condensation pipe; the third cold trap comprises a third condensation pipe and a third semiconductor chilling plate set. The invention further discloses a sampling analysis method for the atmosphere volatile organic compounds. The sampling analysis device and the sampling analysis method can meet requirements on the online monitoring of the contents of the volatile organic compounds and can be used for automatically detecting the contents of the atmosphere volatile organic compounds in an on-site and online manner.

Description

technical field [0001] The invention relates to the technical field of atmospheric environment detection equipment, in particular to an atmospheric volatile organic compound sampling and analysis device and a sampling and analysis method. Background technique [0002] Most of the volatiles contained in the atmosphere are teratogenic, carcinogenic, mutagenic, etc., and are important culprits of atmospheric photochemical hazards and greenhouse effects. Therefore, in order to monitor and control the pollution of the atmosphere in time, the atmospheric volatile organic The real-time detection of the content of volatile organic compounds is increasingly important, especially the online monitoring of the content of volatile organic compounds is increasingly important. At present, the detection of atmospheric volatile organic compounds is mainly done through chromatographic analysis. Since there are many kinds of volatile organic compounds in the atmosphere and their concentration...

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Problems solved by technology

However, this method consumes a lot of liquid nitrogen, and the cost of refrigeration is high. At the same time, liquid nitrogen is replaced in the field, storage is difficult, and the analysis cycle is long, which brings great inconvenience to use and maintenance. Therefore, it is not suitable for continuous on-line monitoring.

Moreover, porous adsorbents are commonly used in low-temperature cold traps in the current technology, which can quickly thermally desorb volatile organic compounds after low-temperature adsorption. In this process, cross-contamination and "memory effect" are easy to occur.

Therefore, the current condensation concentration device and condensation concentration method cannot meet the needs of online monitoring of volatile organic content

In addition, the use of porous adsorbents to adsorb volatile organic compounds takes a long time for desorption, which prolongs the entire analysis cycle and is prone to cross-contamination problems between different sample analyses.

Furthermore, there are many kinds of volatile organic compounds in the atmosphere. When it is necessary to use a gas chromatograph to analyze the content of volatile organic compounds in the atmosphere, it is necessary to analyze dozens or even hundreds of carbon-containing substances. Currently, gas chromatographs are mostly used with A gas chromatograph with a capillary separation column, due to the poor selectivity of a single capillary column to all volatile organic compounds in the atmosphere, results in low separation efficiency. Generally, a capillary column longer than 60m is required to achieve complete separation of substances, resulting in the need for the system to be carried out. High sample pressure requirements, long analysis cycle and other disadvantages

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