Spectrophotometric Determination of Tellurium (IV) with Chrome Azurol S: Application to Sea Water and Synthetic Alloys
Abstract
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.
Keywords
Te, IV determination, Chrome azurol S reagent, Cetyl pyridinium chloride hydrate, Spectrophotometry.Metrics