CHROMIUM SPECIATION BY COLUMN CHROMATOGRAPHY USING A DIRECT-CURRENT PLASMA ATOMIC EMISSION SPECTROMETER

A simple and convenient method has been developed for the separation of CrIII and CrVI in synthetic aqueous solutions on an alumina column (10.0 × 4.0 mm i.d.) attached directly to a direct current plasma atomic emission spectrometer. The readings recorded on an × - y plotter demonstrate that both species of Cr can be retained on the column and then eluted with 0.02 M HNO3 (CrIII) and 1.0 M ammonia solution (CrVI). Low concentrations of Cr can also be detected after separation with the proposed method by passing larger sample volumes through the column. A study of the effect of pH showed that the best separation was achieved between pH 3.0 and 5.5.