“…This exercise is timely because as air becomes cleaner, lower measurement LODs are required so the use of ICP-MS could supersede that of XRFS. In a similar study, a comparison of ICP-MS/MS and PIXE measurements of Al, As, Br, Ca, Cr, Cu, Fe, Mg, Mn, Mo, Na, Ni, Pb, Rb, S, Se, Sr, Ti, V, Zn and Zr in PM 2.5 and PM 2.5-10 lter samples demonstrated 28 that paired-data ratios were mostly ca. 1 except for those of Br, Mg, Na and Zr.…”