Keywords : Sodium dodecyl sulphate
Spectrophotometric Determination of Cerium (III) with Arsenazo III: Application to Sea Water and Synthetic Alloys
Rafidain Journal of Science,
2013, Volume 24, Issue 5, Pages 37-50
The detailed investigation of a sensitive and selective spectrophotometric method for the determination of trace amounts of cerium is described. The method is based on the reaction of cerium(III) with arsenazo ш in the presence of sodium dodecyl sulphate surfactant at pH 3.0 to form a blue-greenish coloured chelate absorbing maximum at 653 nm. Beer’s law is obeyed over the range (5-70) µg /25 ml, with a molar absorptivity of (4.99×104) l.mol-1.cm-1 and the coefficient of determination (r2) is 0.9994, Sandell’s sensitivity index is (28.08×10-4) µg.cm-2, a relative error of (0.0-0.2%) and a relative standard deviation of (0.0 to +2.1)%, depending on the concentration levels in the calibration curve. The method has been applied successfully to determine cerium in sea water and some synthetic alloys.