Investigation of the mass loss of water soluble ionic compounds caused by EDXRF analysis of PM10 loaded filters

• We study influence of EDXRF analysis to mass loss of PM10 loaded filters.
• We test EDXRF applications using vacuum and He/air mixture.
• EDXRF application using vacuum leads to mass losses of PM and ions.
• EDXRF application using He/air diminishes mass losses considerably.
• Vacuum without X-ray energy also leads to mass loss.

The mass loss of particulate matter (PM) due to EDXRF analysis was gravimetrically evaluated on co-located PM10 loaded filters analyzed both using EDXRF under vacuum and using Ion Chromatography. Then, this comparison was repeated with air and helium (He) instead of evacuating the measurements chamber of the EDXRF spectrometer. It was shown that EDXRF application using vacuum medium led to mass loss of water soluble ionic compounds and other volatile constituents of PM10. The use of a He and air medium considerably reduced the PM mass losses. It is demonstrated that the mass loss of PM and ionic compounds mainly resulted from vacuum medium and from a lower extent to the level of X-ray energy. The influence of EDXRF application using vacuum medium on the mass losses of ionic compounds were further investigated. Different amounts of NO3−, NH4+, Cl−, Na+, Mg++ and Ca++ were lost whereas SO4−− and K+ remained unchanged. The relationship between vacuum and application time was also studied for quartz and Teflon filters. The longer the application time, the higher the PM mass loss was observed. The mass loss of PM on quartz filter was shown by experiments to be 2 times higher than on Teflon filter.