Spectrophotometric determination of tellurium (IV)‎ with chrome azurol S : application to sea water and synthetic alloys

Abstract EN

The detailed investigation of a sensitive spectrophotometric method for the determination of trace amounts of tellurium (IV) is described.

The method is based on the reaction of tellurium (IV) with chrome azurol S in the presence of cetylpyridinium chloride hydrate surfactant at a final pH of 3.1 to form a pink coloured chelate absorbing maximum at 525 nm.

Beer’s law is obeyed over the range (5-50) μg / 25 ml, with a molar absorptivity of (2.5 × 104) l.mol-1.cm-1 and a coefficient of determination (r2) of 0.9997.

Sandell’s sensitivity index is (5.104 × 10-3) μg.

cm-2, a relative error of (0.8-0.2 %) and a relative standard deviation of (0.2 to ± 1.8) %, depending on the concentration levels in the calibration curve.

The method has been applied successfully to determine Te (IV) in sea water and some synthetic alloys.