Thiamine undergoes chemical [1,8,9,11,14,16,17,19, 51-54] and photochemical oxidation [55, 56] to form thiochrome (TC) which exhibits a blue fluorescence (440 nm).
fluorimetric determination of thiamine by the thiochrome method," Journal of Pharmaceutical and Biomedical Analysis, vol.
Hu, "Enhanced spectrofluorimetric determination of hypochlorite based on the catalytic oxidation of thiamine to thiochrome in the presence of trace ferrocyanide," RSC Advances, vol.
Because of the low biological concentrations of these analytes, most methods employ precolumn or postcolumn oxidation of thiamines followed by fluorescent detection of thiochrome compounds.
Precolumn derivatization of thiamine yields a fluorescent thiochrome that is isolated by isocratic elution on a reversed-phase HPLC column and detected by fluorescence.
To assess the stability of the thiochrome derivatives, controls and patients samples (n = 25) were assayed immediately after potassium ferricyanide oxidation, then stored at 10[degrees]C in the dark and reassayed after 24 and 48 h.
The oxidation of thiamine to thiochrome
was quantitatively measured by using fluorescence spectroscopy and atomic absorption spectroscopy techniques.
In October 1938, six months after I had joined Kraft, he asked me to use the recently published Jansen thiochrome method to determine the vitamin B 1 (thiamin) in Vegemite.
In the early 1940s, RA Bottomley at Kimptons in Melbourne began to use the thiochrome method to study thiamin in flours and later measure riboflavin.
The chromatographic profile of a blank injection prepared by omitting the thiochrome reaction suggested a lack of interference in sample extracts (Fig.
In addition, the precolumn derivatization procedure uses relatively harsh chromatographic conditions because of the need to use an alkaline mobile phase (pH 7.5-8.0) for the thiochrome derivatives to fluoresce.