Development of helium-microwave-induced plasma-atomic emission spectroscopy system with two-way spectroscopic analysis

This paper reports on a helium-microwave-induced plasma-atomic emission spectroscopy (He-MIP-AES) system with two-way spectroscopic analysis that fulfills the criteria prescribed by the Ministry of Environment, Japan, for measuring the chemical components of particulate matter (PM). The He-MIP-AES system is a reconstruction of a commercial particle analyzer system. In current environmental monitoring systems, PMs are typically collected on trapping filters placed across Japan and classified as either suspended particulate matter (SPM) or PM2.5 depending on the size. The collected PMs are subsequently analyzed with automated measurement instruments such as a piezo balance and with methods such as beta ray attenuation and light scattering. While these measurement methods allow the mass concentration of PMs in the air to be obtained at hourly intervals, the chemical composition of individual particles is analyzed with time-intensive laboratory procedures. In contrast, the presented measurement system allows the chemical compositions and particle sizes to be measured simultaneously in real time.