An aerosol carbonaceous component in-situ online acquisition analyzer and method thereof

Abstract

The invention discloses an aerosol carbonaceous component in-situ online collection analyzer and operation method. The instrument includes a carrier gas and a sampling-analysis gas circuit system. The carrier gas gas circuit system includes He main gas, He purge gas, He / Ox gas and He / CH4 gas gas path; sampling-analysis gas path system includes sampling, desorption-oxidation furnace and analysis gas path; online collection and analysis methods include sampling, purging, OC analysis, EC analysis, methane quantification, methane calibration , instrument cooling and standby. The invention does not set other structures except the quartz film in the laser light path to ensure the accuracy of the light path; it realizes the simultaneous correction of the cutting point by the transmitted laser light and the reflected laser light, and comprehensively reflects the change of the film blackness; the valve body is designed so that the methane internal standard The quantitative error of the gas is greatly reduced, ensuring the stability of the internal standard gas, and improving the accuracy of EC and OC measurement results; the design of the gas path ensures that the carrier gas composition in the system is single and the system background is stable during the analysis stage.

Description

technical field [0001] The invention relates to an environmental quality monitoring instrument, in particular to an aerosol carbonaceous component in-situ online collection analyzer and an online collection and analysis method thereof. Background technique [0002] Carbonaceous components in atmospheric aerosols usually account for 10-70% of the mass concentration of atmospheric fine particles and are an important component of atmospheric fine particles. It can be divided into three categories: organic carbon (Organic Carbon, OC), elemental carbon (Elemental Carbon, EC) and carbonic acid carbon (Carbonate Carbon, CC). OC refers to a mixture containing hundreds of organic compounds (such as aliphatics, aromatics, acids, etc.), mainly derived from emissions from primary combustion processes, biological emissions, and gaseous organic pollutants participating in photochemical reactions and gas particle conversion. process emissions. EC usually refers to a kind of amorphous car...

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Problems solved by technology

However, there are still some deficiencies in the structure and function of commercial online aerosol carbonaceous component analyzers: 1. The cutting point calibration method is single, and only one of the transmission laser calibration method or reflection laser calibration method is used, which cannot comprehensively reflect the film The change of blackness; 2. The heat on the quartz film is mainly transferred from the structure in contact with the quartz film inside the quartz tube and the surrounding air, and the heating is slow and uneven; 3. A quartz sheet is fired inside the furnace tube , it will be polluted during use, which will affect the accuracy of the optical path; 4. The use of carrier gas is wasteful and unreasonably distributed: the methane internal standard gas is discharged throughout the process, causing a large waste; the amount of carrier gas is not constant throughout the analysis process , changing from helium to helium + oxygen will cause background fluctuations and affect the measurement results

5. The structure of the valve body controlling the methane quantitative loop has a large dead volume, which will lead to instability of the methane peak

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