E-Journal of Chemistry (Jan 2007)
Determination of Tellurium(IV) in Various Environmental Samples with Spectrophotometry
Abstract
A rapid, simple and sensitive spectrophotometer method for the determination of traces and ultra traces of tellurium(IV) were studied. These method were based on either the oxidation of leuco methylene green (LMG) to its blue form of methylene green by tellurium in acidic medium, the formed dye shows an absorption maximum at 650 nm in acetate buffer medium (pH 3.0 to 5.0). Beer’s law were obeyed in the concentration range 0.4-2.5 µg mL-1, having molar absorptivity and Sandal’s sensitivity of 4.9×104 L mol-1 cm-2 , and 0.0026 µg cm-2, respectively. The optimum reaction conditions and other analytical parameters were investigated to enhance the sensitivity of the present method. The tolerance limit of various ions with this method has been studied. The proposed method was applied for the analysis of tellurium in spiked, river, lake, spring, waste water samples, plant materials and soil samples. The results obtained by the proposed method were superior to the reported method. The performances of proposed methods were evaluated in terms of student’s ‘t’-test and variance ratio ‘f’-test which indicates the significance of proposed methods over reported methods.