Polarography of titanium in hypophosphorus acid supporting electrolyte

Abstract

Polarographic behavior of titanium in hypophosphorus acid supporting electrolyte has been studied in the view of determination of titanium. Titanium gave a well-defined diffusion-controlled wave in this medium. The log(i/i_d-i) vs. voltage diagram was linear, and its slope corresponded closely to a reversible one electron reduction. The half-wave potential was-0.27 V vs. S. C. E. and i_d/C·m^2/3 ·t^1/6 was 1.43 at 25°C in 1.2M hypophosphorus acid. A linear relationship was obtained between the diffusion current and the concentration over the range of 2.2 ×10^-33.7 × 10^-4M. The precision of the calibration curve for titanium as the standard deviation was 1.77% for concentration of 0.75 × 10^-3M and 3.79% for 0.75 × 10^-4M. Antimony (III) and molybdenum (VI) gave cathodic waves and interfered with the titanium determination. The interference from iron and copper was easily eliminated by boiling the solution with hydrochloric acid and potassium thiocyanate. Hypophosphorus acid as supporting electrolyte was thus especially useful for determination of titanium in the presence of large quantities of iron and copper.