Calixarene hexaacetato derivative for solvent extraction of chromium (III)

Trace concentrations of chromium(III) have been quantitatively extracted wi th 0.0001M hexaacetato calix(6)arene in toluene at pH 6.5. Chromium(III) wa s stripped from the organic phase with 4M hydrochloric acid and determined spectrophotometrically at 520 nm as its complex with xylenol orange. Variou s parameters influencing the extraction such as pH, reagent concentration, nature of diluents and stripping agents and effect of diverse ions have bee n examined. The novelty of the proposed method is that chromium in differen t oxidation states can be separated from each other, apart from its separat ion from iron(III), manganese(II), cobalt(II) and molybdenum(VI). The metho d has been extended to analysis of chromium(III) in real samples such as st ainless steel.