Phase quantification of two chlorothalonil polymorphs by X-ray powder diffraction

The expressions of the calibration curves were given. The relative density of polymorph alpha and beta was estimated to be equal to 0.90. The calibration curves joined into one linear and went through the origin (95% confidence interval). In the mixtures of the two polymorphs, the limits of prediction of alpha content from the determined integral areas mentioned above were less than ±0.026 (95% confidence limits). Some phase transformation samples were determined by the means of this quantitative analysis method.