Simultaneous spectrophotometric determination of copper, nickel and palladium by flow injection analysis

Abstract

A flow injection method has been developed for the simultaneous spectrophotometric determination of ternary and binary mixtures of copper, nickel and palladium. The system involves the sequential measurement of the absorbances of the metal-EDTA complexes at 700, 590, 380 and 340 nm. Sample solutions were buffered at pH 3.2 using a phthalate buffer. The EDTA carrier stream and samples contained 0.5 M sodium nitrate solution and the phthalate concentration in samples was adjusted to 0.08 M to minimise refractive index effects. Solutions could be analysed at rates of up to 100 h^–1, and the relative standard deviation was less than 1%. The effects of the length of the dispersion coil and the sample volume on the FIA-spectrophotometric signals are presented.