Rapid spectrophotometric determination of boron in steel

A rapid spectrophotometric method is presented for the determination of boron in steel by use of the fluoborate-Methylene Blue complex. The method is in principle similar to that of Rosotte, but modifications simplify the operation, obviate contamination and avoid problems with emulsion formation. Up to 20% Cr, 10% Ni, and 1% each of V, Mo and W present either individually or collectively do not interfere in the determination, making it applicable to alloy steels. The determination limit of the method has been lowered from 5 to 0.2 ppm boron. Samples are dissolved at room temperature in polythene bottles, solubilizing all forms of boron including boron nitride, and avoiding loss of relatively volatile boron compounds. The precision of the method is good. Six samples can be analysed in less than 2 hr.