Real time bipolar time-of-flight mass spectrometer for analyzing single aerosol particles

This paper describes a new built single particle laser desorption/ionization time of flight mass spectrometer capable of determining the size and chemical compositions of individual aerosol particles in real-time. The instrument was compactly designed with bipolar grid reflectron mass analyzers for higher mass resolution. It measures 90 cm long × 70 cm wide × 170 cm high, weights ∼170 kg and has a total power consumption of less than 2000 W. Standard polystyrene latex particles (PSL) and metallic solution were used to perform size and mass calibration, respectively, and the effect of inlet pressure of the aerodynamic lens on size calibration was also investigated. The instrument was first used for the ambient aerosol detection in Guangzhou City, China, and the preliminary measurements show its’ ability to characterize the atmospheric aerosol particles containing different chemical compositions with diameters ranging from 250 to 2000 nm and a total hit rate above 30%. The preliminary measurements also show that the aerosol particles in Guangzhou, China can be mainly classified into five types, which are rich K, rich Na, Nark, carbonaceous, and metal containing, and their formations are also generally discussed.

This paper describes a new built single particle laser desorption/ionization time of flight mass spectrometer capable of determining the size and chemical compositions of individual aerosol particles ranging from 250 nm to 2000 nm in real-time.Figure optionsDownload high-quality image (180 K)Download as PowerPoint slideResearch highlights
► A new built aerosol mass spectrometer capable of determining the size and chemical compositions of individual particles ranging from 250 nm to 2000 nm in real-time and achieving a total hit rate above 30%.
► The mechanical structure of the instrument is compact and the vacuum system is simplified.
► Bipolar grid reflectron mass analyzers with ion focus technology increase the mass resolution and ion transmission efficiency.
► The preliminary ambient aerosol detection shows that it has great potential applications in environmental aerosol measurements and laboratory aerosol mechanics researches in China.