抄録
The previous paper had shown that the red fluorescent product was formed by reaction of thiolized-thiamine with cuprous ion, and it could be applied to the analysis of thiamine in spot test and extraction method. In this paper, a new method for the fluorometric determination of thiamine with copper was established. The cuprous ion reagent was prepared by reduction of cupric sulfate with hydroxylamine sulfate, and adjusting pH to 7.2-7.8. The sample solution of thiamine was thiolized with sodium hydroxide solution at pH 11.0-12.0,and then heated for 30 seconds at 70℃. The reaction product of cuprous-thiolized thiamine system was extracted with isoamyl alcohol containing 30 μg/ml isoamyl gallate as a stabilizer, and then intensity of red fluorescence of isoamyl alcohol layer at 640mμ excited by 320mμ rays was then measured. The working curve of thiamine in this method was almost straight for 2-30 μg/ml. This determination was interfered with Hg^<2+>, Na_2S, oxine, sulfathiazole and riboflavin.
