Simultaneous Spectrophotometric Determination of Co2+, Ni2+ and Cu2+ in Industrial Alloys Using Partial Least Squares Method

Spectrometric multicomponent analysis is a subject of great practical importance in the environmental, clinical, pharmaceutical and cultural heritage areas. Partial Least Squares (PLS) modeling based on SIMPLS algorithm was applied for the simultaneous spectrophotometric determination of Co(II), Ni(II) and Cu(II) with ammonium purpurate (murexide) as the complexing agent. An analytical wavelengths of (400 to 490) nm were chosen and an experimental calibration matrix for PLS was designed with 21 samples of (0.354 to 5.893) μg/mL, (0.352 to 5.869) μg/mL and (0.381 to 6.355) μg/mL for cobalt, nickel and copper, respectively. A leave one out cross-validation procedure was used for selecting the number of components using PRESS. The method was successfully applied to the simultaneous determination of these metals in industrial alloys.