Spectrophotometric Determination of Trace Amounts of Selenium Based on Catalytic Reduction of Toluidine Blue by Sulfide Ion

Publisher Website
Google Scholar
Abstract
A simple, rapid, and sensitive kinetic method for the determination of trace selenium (0.03–1.5 μg cm−3) based on its catalytic effect on the reduction reaction of toluidine blue and sodium sulfide is reported. The reaction is monitored spectrophotometrically by measuring the decreasing absorbance of toluidine blue at 605 nm by the variable time method. The detection limit is 8 ng cm−3 and the relative standard deviation for 1 μg cm−3 selenium is 1.4%. The procedure was successfully applied to the determination of selenium in real samples.