A Colorimetric Determination of Micro Amounts of Baron, and Its Applications for the Analysis of Beryllium Metals

Abstract

The accurate determination of minute amounts of boron contained in materials and fuels for reactors is one of the very important problems because of the large cross section of boron for thermal neutrons.
The method studied by the present authors is based on the coloration of boron with curcumin.
The procedure is as follows.
Methanol and sulphuric acid are added into a distilling flask and 25ml of methanol is distilled to expel boron contained in the reagents. A sample containing 0.052μg of boron is weighed into the distilling flask, and dissolved in sulphuric acid.
Immediately 2025ml methanol is distilled and the distillate is caught in calcium hydroxide suspension.
After evaporating the suspension to dryness on a water bath, hydrochloric acid and oxalic acid-curcumin are added and the dish is placed in a thermostat held at temperature of 58±0.5°C.
The boron complex is extracted from the residue with ethanol and the color is measured at the wave length of 540mμ.
This method makes it possible to determine 0.050.1ppm of boron within the error of 5%, and is applied to determine the amount of boron in metal beryllium and beryllium hydroxide.