Indirect complexometric determination of palladium usingl-histidine as masking agent

An indirect complexo-titrimetric method is described for the determination of palladium in the presence of other metal ions, L-histidine being used as the masking agent. Palladium(II) and other metal ions are initially complexed with an excess of EDTA and the surplus EDTA titrated with standard zinc sulfate solution at pH 4.5–5.5 using xylenol orange as indicator. An excess of 1 % L-histidine solution is then added, and the released EDTA is titrated with standard zinc sulfate solution. Accurate and reproducible results were obtained for 2–15 mg of Pd with relative errors 0.4% and standard deviations < 0.02mg. Sn(IV) and Au(III) interfere, but can be easily masked. The method is successfully applied for the determination of palladium(II) in alloy compositions.