Determination of boric anhydride content in boron powder

Methods of determination of boric anhydride content in boron powder based on boric anhydride dissolution in water and its further determination by difference between the evaporation rates of solution and standard (distilled water) are suggested. To dry the initial powders the temperature of 70 deg C and time of 6 hours are optimal. At the given parameters (the sample weight -0.1g, operating temperature 70 deg C, distilled water volume - 15 ml), the suggested method permits to estimate quantitatively boric anhydride concentration in boron powders with the sensitivity up to 10 -2% mass with the relative standard deviation of sensitivity limit being 0.2