Abstract: Anew method of complexometric titration for determination of mixed metal ions with principal component regression(PCR) was developed. The principle of this method was described and the linear complexometric titration equation was derived. In this work, a mercury film electrode(MFE) was used as the indicator electrode for potentiometric measurements, and a double junction Ag/AgCl electrode as the reference electrode. The mixtures of metal ions were titrated with ethylenediamine teraacetic acid(EDTA), the potentiometric titration data were recorded at each selected potential points and were then treated by chemometric approach of PCR. A set of synthetic mixtures of lead, copper, zinc and cobalt with concentration levels from 0.5 mmol/Lto 1.5 mmol/Lwere analyzed by the proposed method and acceptable results were obtained.

Key words: Complexometric titration, Metal ions, Mercury film electrode, Principal component regression