Distillation isothermique de l'acide borique sous forme d'ester tr1méthylborique

The quantitative separation by isothermal distillation of 50–100 ng of boron in 0.1 ml of sulfuric acid solution is possible in 10 min. if the sulfuric acid solution is made to react with 0.3 ml of methanol, and the trimethylboric ester formed is absorbed by 0.3 ml of sodium hydroxide solution at a concentration of 2 μg ml^-1. Boron in the distilled fractions is measured by a fluorimetric method with HMCB.