DETERMINATION OF BORIC-ACID IN NICKEL-PLATING BATHS USING A TETRAFLUOROBORATE SELECTIVE ELECTRODE

Since the analytical control of boric acid contents in nickel plating baths is important, we developed a potentiometric method, using tetraf luoroborate selective electrodes. The boric acid contained in the samp les was converted into tetrafluoroborate anions by means of a fluorifi cation process; afterwards this ion was determined by the sample addit ion method. The precision and accuracy of the recommended procedure, e xpressed in terms of average variation coefficient (1.2%) and average percentage of spike recovery (99.6%), were better than those obtained by application, on the same samples, of the mannitol method (the refer ence technique).