Determination of enantiomeric excess of leucine and valine by X-ray powder diffraction

Accurate determination of X-ray energies using powder diffraction

We report synchrotron energy determinations using the powder diffraction patterns of Si (640b) and LaB6 (660) standard reference powders at a number of energies between 5 and 20 keV. The fitted peak positions of all peaks recorded on image plates were used in each energy determination. Several sources of systematic error were investigated and their connection led to physically reasonable and co...

X-Ray Powder Diffraction Metrics

To compare sample data from x-ray diffraction a suitable metric is developed to evaluate the similarity (or dissimilarity) between samples and to compare it to a references. The methodology focuses on the d-lines and uses the intensity measurements indirectly in the algorithm. The resulting d-line distribution and summary statistics of the differences is used to establish whether a true differe...

Determination of the degree of deacetylation of chitin and chitosan by X-ray powder diffraction.

A new method to determine the degree of deacetylation (DD) of alpha-chitin and chitosan in the range of 17-94% DD using X-ray powder diffraction (XRD) is proposed. The results were calibrated using (1)H NMR spectroscopy for chitosan and FTIR for chitin, in comparison with the potentiometric titration method. The results showed a good linear correlation between the CrI020 from XRD and the calibr...

Surface Hardness Measurment and Microstructural Characterisation of Steel by X-Ray Diffraction Profile Analysis

An X-ray diffraction line will broaden considerably when steels change into martensitic structure on quenching. The results presented in this paper show that X-ray diffraction technique can be employed for a rapid and nondestructive measurement of hardness of hardened steel. Measurement on various quenched and tempered steels showed that the breadth of its diffraction peak increased with increa...

Two-dimensional X-ray powder diffraction