Theretical and practical approach in determining matrix effects in quantitative XRF analysis

analysis of rocks by XRF. These effects can be corrected by using ap- propriate experimental or calculated algorythms, starting from a set of reference samples using multivariate regression methods. In this work, we propose a simple method to evaluate the expected matrix effects for major elements, on the basis of the XRF total mass attenuation coefficients available in the literature. The obtained results confirm that theoretically calculated matrix ef- fects are compatible with those experimentally observed. The proposed method makes it easier to choose an appropriate cali- bration set for routine analysis, allowing for a reduction in the number of standards to be used, or in case it is necessary to activate a new analytical line.