POLAROGRAPHIC STUDIES IN AQUEOUS HYDROFLUORIC ACID USING AC AND DC RAPID TECHNIQUES

Conventional polarographic procedures cannot be used in hydrofluoric acid solutions because of etching of the glass capillary of the DME. However, very rapid polarographic techniques with both ac and dc polarography have been shown to be effective because insignificant glass attack occurs in the short scan time. The necessity of constructing a DME from Teflon (Du Pont) or other hydrofluoric acid resistant material is therefore removed. The method has been applied to the systems Cd(ll), Tl(l), Pb(ll), Sn(ll), Bi(lll), Mo(VI) and U(VI) in 5 to 40% hydrofluoric acid solutions. The polarographic characteristics of most electrode reactions studied in aqueous hydrofluoric acid are consistent with those expected in a solution containing a weak acid. Analytically, the most significant feature is that, for any particular concentration of metal, the value obtained in most cases is independent of wide variations in the hydrofluoric acid concentration. This simplifies analysis of mineralogical and metallurgical samples which must be dissolved in hydrofluoric acid. © 1969, American Chemical Society. All rights reserved.