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 tetrafluoroborate selective electrodes. The boric acid contained in the samples was converted into tetrafluoroborate anions by means of a fluorification process; afterwards this ion was determined by the sample addition method. The precision and accuracy of the recommended procedure, expressed 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 reference technique).