Aerosol mass spectrometer with particle size selection

Abstract

The invention applies for an aerosol mass spectrometer with particle size selection, wherein the aerosol mass spectrometer can simultaneously select the particle size, the concentration and the chemical component of the atmospheric aerosol. The aerosol mass spectrometer uses a sampling hole with the diameter of 100 micrometers to carry out direct sampling on an aerosol in a natural environment; aerosol particles are focused into a particle beam flow with the 0.5-milimeter diameter by a pneumatic focusing lens; the aerosol particles are selected by a particle size selector that is formed by three coaxial rotating plates with slits, wherein the rotating plates of the particle size selector are driven by a synchronous motor and the frequency of the synchronous motor power supply can be adjusted continuously; an aerosol particle that is selected by the particle size selector is gasified by a gasifier with the high temperature from 600 to 700 degrees; gas after gasification is ionized by an electron collision ionizer; a generated ion is detected by a W type reflection type mass spectrum apparatus so as to obtain the mass spectrum of the aerosol. Therefore, information including the particle size, the concentration and the chemical composition of the organic aerosol can be obtained by analyzing the sampling rate, the frequency of the synchronous motor power supply and the obtained mass spectrum.

Description

Technical field [0001] The invention relates to a particle diameter selective aerosol mass spectrometer, which can measure the particle diameter, concentration and chemical composition of atmospheric aerosol particles online. Background technique [0002] In recent years, aerosol pollution has become the main form of air pollution in large and medium-sized cities in my country. Aerosol pollution not only endangers the health of citizens, but also affects the image of the city, traffic and many other aspects. With the economic growth and the improvement of people's living standards, the monitoring and control of aerosol pollution has become a primary issue in the urban environment. The chemical composition of atmospheric aerosol is very complex, it contains various trace metals, inorganic oxides, sulfates, nitrates, hydrocarbons and oxygen-containing organic compounds. The traditional aerosol composition analysis method is to use a collector to collect the aerosol, and then ...

AI Technical Summary

Problems solved by technology

[0004] Aerosol mass spectrometers with different technical routes have different characteristics. Aerosol mass spectrometers based on electron impact ionization technology can analyze most inorganic and organic substances, and can perform quantitative analysis, but cannot gasify refractory substances such as carbon dioxide silicon etc.

The aerosol mass spectrometer based on laser analysis and ionization technology can analyze / ionize all substances, and can be used to study refractory particles such as sand and dust. It has high sensitivity and has obvious advantages in analyzing metal elements in aerosols. Its disadvantage is quantitative measurement. poor performance

Images