Source apportionment of aerosol particles using polycapillary slightly focusing X-ray lens

A micro-X-ray fluorescence (Micro-XRF) spectrometer based on a polycapillary slightly focusing X-ray lens (PSFXRL) and laboratory X-ray source was designed to carry out the source apportionment of aerosol particles. In the distribution curve of the X-ray intensity in the focal spot of PSFXRL, there was a plateau with a diameter of about 65 μm. The uniformity of this plateau was about 3%. This was helpful in measuring the XRF spectrum of a single aerosol particle in which the element distributions are not uniform. The minimum detection limit (MDL) of this Micro-XRF spectrometer was 15 ppm for the Fe-Kα. The origins of the aerosol particles at the exit of a subway station and a construction site were apportioned. This Micro-XRF spectrometer has potential applications in analysis of single aerosol particles.