DETERMINATION OF TELLURIUM BP GAS-PHASE MOLECULAR ABSORPTION SPECTROMETRY AFTER HYDROGEN TELLURIDE GENERATION

A method for determination of tellurium(IV) or tellurium(VI) is described that involves hydrogen telluride generation by reduction with sodium tetrahydroborate(III), evolution of hydride with HCl solution, transport into a flow-cell placed in a UV-visible molecular absorption spectrophotometer and measurement of gas at 190 nm. Hydride generation and determination procedures are optimized, based on height and area of absorbance versus time profile of hydrogen telluride generated. Using the best experimental conditions found the calibration curve is linear from 5 to 100 mu g/ml of tellurium, 1.1 mu g/ml of tellurium(IV) or 3,1 mu g/ml of tellurium(VI) can be detected, and relative standard deviation ranges from 4 to 7%. The method is applied to the analysis of additives for synthetic rubber making.