Indirect Polarographic Determination of Boron.

Abstract

Sir : In a recent publication, Abbott and Goliat (1) have shown that the polarographic reduction of 1,4-benzoquinone (quinone) can be used for the indirect determination of certain acids.In this study, the procedure of Abbott and Goliat was adapted, with minor modifications, to the analysis of boron in glass and colemanite. The boron content of these materials is usually determined by methods which utilize the titration of the mannitol-boric acid complex with standard base; however, the preliminary separation of boron from the hydrolyzable sample ions is always required in order to obtain sharp and accurate end points (8).The prior separation of boron is omitted in the procedure outlined in this paper. Support for by-passing this step is provided by the results of numerous preliminary tests and the analysis of both synthetic and standard samples.These results indicate that under the conditions and techniques of the proposed method, low concentrations of hydrolyzable ions in the polarographic solution do not adversely affect the boron evaluation. By circumventing this step much time is saved, and a possible source of error is avoided.About 20 minutes is required for a single determination.