RAPID AND SENSITIVE SPECTROPHOTOMETRIC DETERMINATION OF CERIUM(IV) WITH 2,4-DIHYDROXY BENZOPHENONE BENZOIC HYDRAZONE

A simple and sensitive spectrophotometric method for the determination of cerium(IV) in an aqueous medium is reported. The metal ion formed a 1:1 orange-red coloured complex with 2,4-dihydroxy benzophenone benz oic hydrazone (DHBPBH) at pH 10.0 showing an absorption maximum at 400 nm. The molar absorptivity and Sandell's sensitivity of the method ar e found to be 2.0 x 10(4) 1/mol/cm and 0.007 mug/cm2, respectively. Be er's law is obeyed in the range 0.7-7.0 mug/ml. Titanium, vanadium and molybdenum do not interfere. The extent of interferences by other ion s is presented. The method is applied for the determination of cerium in simulated rock samples.