Flow injection determination of thiamine based on its oxidation to thiochrome by mercury(II)

Abstract

The reaction involving the oxidation of thiamine to fluorescent thiochrome by mercury(II) in basic solutions has been adapted to flow injection. Linear calibration graphs were obtained between 2 × 10^–7 and 7 × 10^–6M, with a sampling rate of 22 samples h^–1 and a relative standard deviation of 0.42–0.17%. The applicability of the method to the determination of thiamine in vitamin-mineral preparations was demonstrated by investigating the effect of potential interferences and by the analysis of commercial preparations.