Comparison of different X-ray fluorescence analysis methods of total element content in soil

Soil is a heterogeneous material and large variations in its chemical and physical nature can occur in a random samples collected in a small area of apparently similar land. Environmental analyses of soils call for rapid quantitative analysis techniques. X-ray fluorescence analysis has been used for many years and various sample preparation methods and analysis techniques have been used. Sample inhomogeneity is a very critical aspect of such a multielement analysis technique because rather small amount of soil generally are used for analyses. The aim of the current report is to compare different x-ray fluorescence techniques and sample preparation methods. Soil samples were collected from two different places in Botswana: Serowe and Gaborone.Three different x-ray fluorescence analysis techniques were used in the analysis of sandy soils. Two of them were energy-dispersive x-ray fluorescence spectrometers. The third was a total -reflection x-ray fluorescence spectrometer. A comparison shows that TXRF gives comparable results to EDXRF (second method). All results were within 10-15%. The conclusion is that TXRF is a suitable method not only for chemical speciation of soil, but also for the analysis of total fraction of elements