Multicomponent determination of cobalt, copper, and iron with 1,10-phenanthroline by principal component regression modelling of spectrophotometric data

A spectrophotometric method for the simultaneous determination of Co, Cu, and Fe in ternary mixtures by means of 1,10-phenanthroline as a complexing agent was developed. The influence of chemical variables affecting the analytical reaction was evaluated. A principal component regression procedure was used to assess spectrophotometric data obtained from nineteen calibration solutions. The method was validated by applying it to the analysis of synthetic mixtures over the concentration ranges 0-407 mu mol Co/L, 0-189 mu mol Cu/L, and 0-143 mu mol Fe/L. It was also successfully employed for the analysis of two cobalt magnetic alloys. The relative errors in the determinations were less than 7% in most cases.