Abstract
A simple spectrophotometric method is described for the determination of microamount of boron invarious steels by solvent extraction with tetrafluoroborate-methyleneblue complex. The procedure is asfollows:
Dissolve 1g of the sample in 20m1 of HNO3 (1: 1) or 20 ml of aqua regia, add 15 ml of H2SO4 (1: 1) and 15m1 of H2PO4 (1: 1), evaporate to fumes of H2S04, cool, and dilute to 250ml withwater. Transfer 25 ml of the solution to separatory funnel, add 10 ml of water and 5 ml of HF (5%) and let stand for I hr. Add 20 ml of water, 2 ml of methyleneblue solution (0.001M) and 25 ml ofdichloroethane, and shake for 1 min. Let stand for 5 min to allow the layers to separate. Filter thedichloroethane solution through a dry filter paper in to a dry absorption cell. Measure the absorbanceagainst blank solution at 660mμ. The procedure needs less time than any other methods reported in the past literature.
