Non-Destructive Determination of Bromine in Salt Samples by X-Ray Fluorescence Method

Abstract

A dried sample of 10-15g was ground by a vibrating mill for 4min, and pressed into an aluminum ring (40mm i. d., 5mm high) under a total pressure of 30 ton to make a sample briquet. Peak intensities for BrK_α and ClK_α of the briquet were measured by the method of fixed time, 100 and 10s, respectively. Background intensities were also measured and subtracted from the peak intensities to get net intensities. Standard samples for calibration curves were prepared by addhig known amounts of sodium bromide to a high-purity sodium chloride. Linear calibration curves were obtained of both BrK_α intensity and BrK_α/ClK_α intensity ratio vs. bromine concentration of up to 700ppm. Relative standard deviation was about 1.5% for determination of a refined salt containing 65ppm bromine, and the detection limit of bromine was estimated as about 3ppm. The pulverization and mixing of samples were critical. Analytical results by the proposed method agreed well with those by ion chromatography.