Determination of iron and nickel in water and brine by solvent extraction and atomic absorption spectroscopy

A rapid, reliable and sensitive atomic absorption method for the determination of traces of iron and nickel in concentrated brine and in water has been developed. A simple, single extraction procedure is effective for iron in water at concentrations of 0.4–200 p.p.b. and in 25% (w/w) sodium chloride solutions at concentrations between 0.8 p.p.b. and 200 p.p.b. A similar procedure has been developed for nickel concentrations in the range 2–200 p.p.b. in water and 4–200 p.p.b. in brine. Extraction for 15 min with MIBK from a system buffered at pH 7 yields optimum results. The complexing agents are 0.2% solutions of 8-hydroxyquinoline and dimethylglyoxime for iron and nickel, respectively.