Rigaku Corporation has published an application report on its global website demonstrating the utility of X-ray diffraction (XRD) in the analysis of bulk samples with curved surfaces. The analysis described highlights the capabilities of the Rigaku MiniFlex general purpose X-ray diffractometer.
Powder X-ray diffractometers can readily measure bulk samples, given appropriate sample preparation techniques and measurement conditions. When measuring samples such as pharmaceutical tablets, which have curved surfaces, various effects are seen due to the curvature. These can include shifting of the diffraction angle and widening of the full width at half maximum. As demonstrated in the report, in cases of samples with these kinds of surfaces, adjustments can be made so that the sample surface is at the same height as the reference surface of the sample plate, reducing the effects of curvature. The effects can be further reduced by performing the measurement while narrowing the divergence slit and the incident height-limiting slit.
The example presented in the report shows that it is possible to identify the active ingredients in tablets such as ibuprofen and ethenzamide.
The bulk sample article, along with other pharmaceutical-related XRD analyses, can be seen at: https://www.rigaku.com/en/products/xrd/miniflex/apps/11
The newly introduced sixth generation MiniFlex X-ray diffractometer is a multipurpose analytical instrument that can determine phase identification and quantification, percent (%) crystallinity, crystallite size and strain, lattice parameter refinement, Rietveld refinement, and molecular structure.