Influence of and correction for moisture in rocks, soils and sediments on in situ XRF analysis

This paper discusses the influence of water contained in rocks, soils and sediments on in situ XRF analysis with a portable XRF analyzer. Water in natural rocks, soil and sediments absorbs the characteristic x-rays from the elements and also causes the primary radiation from the excitation sources to scatter, which results in a decrease in the intensity of characteristic x-rays and an increase in the intensity of scattered x-rays in a fluorescence spectrum. A method for correcting for the influence of the water on the analysis of wet samples is proposed, based on the fact that the intensity of scattered radiation is directly proportional to the water content of wet samples. Tests on a set of wet soil samples showed that the method can effectively correct for the influence of the water in wet samples up to a 20% water content. The method was also applied to the analysis of soil with an IED-2000P XRF analyzer in a copper prospecting area in Yunnan, China. The results show satisfactory agreement of the results for Cu, Zn and Sr analyses before and after rain. Copyright (C) 2005 John Wiley Sons, Ltd.