Solvent-extraction separation of manganese(II) with calixarene substitutedwith an acetyl group at the lower rim

A trace level concentration of Mn(II) was quantitatively extracted at pH 6. 0 with 1x10(-4) M of hexaacetatocalix(6)arene in hexane. Manganese(II) from the organic phase was stripped with 2 M sulfuric acid and determined as it s iodo complex spectrophotometrically at 545 nm. The various parameters inf luencing extraction, such as pH, reagent concentration, nature of diluents, stripping agents, and effects of diverse ions, were studied to determine t he optimum conditions for the separation of Mn(II). Manganese(II) was separ ated from Fe(III), Th(IV), Cr(III) as well as alkali and alkaline earth ele ments which are generally associated with it in a complex mixture. The meth od was extended for an analysis of Mn in real samples, such as minerals, al loys and pharmaceutical samples. The method is reproducible with a relative standard deviation of +/- 1.2%.