Dissolution and Assay of Elemental Boron.

Isotope dilution assay of boron-10 enriched elemental boron by mass spectrometry

“…For many years, the study of metastable ions had been confined mainly to physical chemistry. In recent years, however, the usefulness of metastable ions in the analysis of mass spectra of organic molecules has been clearly demonstrated (1). Rapid progress in this field has been achieved due to the pioneering work of Beynon, McLafferty, and others.…”

“…This method is time-consuming, requiring at least two days, and suffers from the necessity for frequent blank determinations. Other methods of boron assay including pyrohydrolysis separatiop of boric acid followed by titration (1), spectrophotometric determination as the boric acid-diaminochrysazin complex (2), and gravimetric determination of boric acid with nitron (3) do not offer greater precision or appreciable time savings. The relative standard deviation for replicate determinations by any of these methods is about 0.1%.…”

Determination of Boron in Refractory Borides by Pyrohydrolysis.

“…has been the most popular method of detecting the end point of the U(IV)-Fe(III) reaction {6, 7). However spectrophotometry (4), amperometry (4, 9), and visual indicators (5) have also been used with varying success.…”

“…Recent work (6,8) has suggested that the pyrohydrolysis of boron compounds proceeds in two steps: first, the water oxidation of the boride and second, the transport of the gaseous HB02 or H3BO3 formed. The reaction of a metal boride with steam would presumably be the following:…”

“…Average of five or more determinations. 6 Total impurities determined by quantitative spectrographic analysis.…”