Accuracy of XRPD QPA using the combined Rietveld-RIR method

The accuracy of the estimate of the weights calculated from the quantitative phase analysis (QPA) of complex mixtures which contain zeolites and clays using the combined Rietveld and reference intensity ratio (RIR) methods is assessed. The influence of fundamental factors, such as the choice of the structure model, the amount of added internal standard and the displacement parameters, is considered.