Optimization of X-ray fluorescence elemental analysis: an example from Kenya

A systematic study and application of a radioisotope excited energy dispersive X-ray fluorescence analysis method to multi-elemental determination in Kenyan rock samples whose supporting matrices are of light elements is presented. The method consists of instrumentation and analytical parameter optimization, and an empirical background stripping model for reduced dark matrix scatter effects. The method was applied to trace, minor and major elemental determination in rock samples collected from various parts of Kenya in order to test it for routine mineral and geochemical prospecting in light element geological matrices. A correlative analysis of the samples revealed a common presence of elements: K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, Ga, Au, Pb, Br, Rb, Sr, Nb, Zr, As and Y in all five types of rocks, down to 3.0 μg g−1 for Br, with major differences revealed in the rock tectonic setting, origin, age and related palaeomagnetic parameters, and mineral enrichment prospects.