Spectrophotometric determination of cerium (III)‎ with arsenazo III : application to sea water and synthetic alloys

الملخص EN

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 4-10 X 28.8 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.