Fluorometric determination of periodate with thiamine and its application to the determination of ethylene glycol and glycerol

The fluorometric determination of periodate with thiamine (VB1) and its application to the indirect determination of organic compounds have been developed. Thiamine can be oxidized to thiochrome by potassium periodate and the reaction can be accelerated by manganese (II). Thiochrome, belonging to fluorescent species, has the excitation and emission maxima at 397 and 454 nm, respectively. Under the optimum conditions, responses for the periodate determination were linear between 5.0×10−7–1.8×10−5 mol l−1. The detection limit, corresponding to a signal to noise ratio of 3, was 2.6×10−7 mol l−1. The relative standard deviation (n=5) was 1.0%. The proposed method was applied to the indirect determination of several organic compounds via the Malaprade reaction and good results were obtained.