Compleximetric determination of palladium(II) using sodium oxalate as a selective masking agent

A selective compleximetric titrimetric method is described for the determination of paliadium(II), sodium oxalate being used as a masking agent. Palladium present in a given sample solution is first complexed with a known excess of EDTA and the excess of EDTA is titrated against zinc sulfate solution at pH 4.5-5.5 (acetic acid - sodium acetate buffer) using xylenol orange as indicator. A known excess of sodium oxalate solution in water (1%) is added, the mixture is shaken well and EDTA released from the Pd-EDTA complex is titrated against standard zinc sulfate solution. Reproducible and accurate results are obtained for 2.0-20 mg of Pd with relative errors +/-5%. The interferences of various ions were studied. The method was applied to the determination of palladium(II) in its alloy compositions and complexes.