A Rapid, Selective and Sensitive Spectrophotometric Method for Determination of Cerium(IV)

Department of Chemistry, Jadavpur University, Calcutta-700 032
Manuscript received 31 August 1984, revised 17 May 1988, accepted 17 August 1988

A better selective, sensitive, simple and rapid chloroform extractive spectrophoto­metric method for the determination of cerium(iv) using o-iodobenzoyl-o-tolylhydroxyl­amine (OIBOTHA) has been developed. The colour system of Ce^IV -OIBOTHA, extracted from ammoniacal medium, in the presence of α-picoline, obeys Beer's law at \(\lambda\) _max. 450 urn for 0.40 - 32 ppm of Ce^IV, the optimum concentration range being 1.5 — 30 ppm. The percentage relative error is 2.65% according to Ayer's equation, the molar absorptivity 5.744 x 10² dm² mol^-1 cm^-1 and the Sandell sensitivity for an absorbance of 0.001 is 0.0244 \(\mu\)g cm^-2. The stoichiometric composition of the complex is found to be 1 : 4 (metal - ligand), Over forty cations and anions do not interfere. The method has been tested on few synthetic samples containing cerium(iv) and the result are encouraging.