VOLTAMMETRIC DETERMINATION OF INDIUM IN ALUMINA-SUPPORTED CATALYSTS

A sensitive and rapid method for the estimation of trace levels of indium in alumina supported catalysts using square wave voltammetry (SWV) is discussed. The SWV method for indium in the alumina matrix is standardized using synthetic samples and good recoveries were obtained. Calibration graphs are linear in the range 1-5 mug/ml and the detection limit is 3.57 x 10(-8) g/ml. In order to determine the accuracy of the proposed method, the results obtained have been compared with those given by atomic absorption spectrophotometry (AAS). Statistical analysis shows no significant bias between the two methods. This technique is found suitable for the estimation of indium in the range 0.1-1.0% (w/w) in the catalyst samples with an RSD < 1.5%.