Rapid spectrophotometric determination of copper in steel and non-ferrous alloys after synergistic extraction

Abstract

A simple and rapid procedure is described for the separation and determination of copper in steel and alloys comprising extraction of the copper into chloroform with isonitrosoacetylacetone (H-INAA) in combination with pyridine from an aqueous solution of pH 6.2. The extracted species absorbs at 450 nm; the molar absorptivity is 2.44 × 10³ l mol^–1 cm^–1 and Sandell's sensitivity is 2.6 × 10^–2µg cm^–2. Beer's law is obeyed over the range 20–125 µg of copper per 10 ml of organic phase. The complex is stable for 48 h and the extracted species is probably Cu(INAA)₂.2C₆H₅N. Copper is separated from associated elements. Results of the analysis of synthetic mixtures and standard samples are reported.