Abstract

The conditions for splitting up polymeric zirconium ions in order to carry out a quantitative complexometric titration of Zr4+ have been examined. Under the proposed procedure up to 35mg Zr are titrated with a solution of EDTA (0.03 mol/l) in a nitric acid medium (CHNO3 =1 mol/l) with xylenol orange indicator after boiling the solution for 3 min.

TiO2+, Al3+, Fe3+, Ca2+, Na+, Zn2+ and Co2+ which may be present in tanning salts and leathers do not interfere with the procedure. There are no systematic errors in the analysis of ZrO2 in solutions of melts of the ash content of leathers.