COMBINED DEVICE FOR GRAVIMETRIC AND CHEMICAL ANALYSIS OF AEROSOLS Russian patent published in 2019 - IPC H01J49/26 G01N15/02 

FIELD: physics.

SUBSTANCE: invention relates to mass analysis means, is intended for gravimetric and chemical analysis of aerosols for detection, identification and quantitative determination of chemical compounds in laboratory, production and field conditions and enables to determine distribution by size, counting and mass concentration of aerosol particles in gas and aerosol phases of air-dispersed media. Device based on mass spectrometer comprises corona electrode and counter electrode for charging aerosol particles in corona discharge between electrodes, program-controlled high-voltage pulse voltage source with corona discharge current stabilizer connected to corona-forming electrode, counter-electrode supply source and corona discharge current meter connected to counter electrode, which detects ion currents of packets of particles passing through the discharge gap at different speed and deposited on the counter electrode. Counter electrode is made mesh with 50–90 % transparency for particles in corona discharge, provides deposition and accumulation of aerosol particles on grid and is equipped with power supply providing heating to preset temperature and programmable thermal desorption and evaporation of aerosol particles deposited on the mesh for their preliminary separation and programmable thermal decomposition of the settled non-volatile and low-volatile substances to obtain their mass spectra. Counter electrode is conjugated with mass spectrometer by means of input device in form of selective membrane. Data control and data recording unit is connected to the high-voltage pulse supply source of the corona-forming electrode, the corona discharge current meter of the corona-forming electrode, the counter electrode supply source and the mass spectrometer ion detector.

EFFECT: high sensitivity of analysis by reducing detection thresholds of components of the aerosol phase owing to accumulation thereof on the counter electrode, high reliability of identifying substances by programmed thermal desorption and preliminary separation of components of the aerosol phase, as well as by obtaining mass spectra of volatile products obtained after thermal decomposition of non-volatile and low-volatility substances sorbed on deposited dust particles.

7 cl, 6 dwg