重クロム酸加里-酸化法によるタンニンの定量法に就て-

概要

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The permanganate titration method of tannin estimation with indigo carmine as indicator, gives us unsatisfactory accuracy on account of its unsharp endpoint. So attempting to establish more accurate volumetric oxidation method we devised the bichromate method applied iodimetry. We used gallic acid as the standard substance and determined the gallic acid factors which mean the equivalent amount of gallic acid to tannin containing in va rious vegetable tanning materials on each reducing capacity of tannins against boiling bichromate-sulfuric acid solution.Actual tannin contents are found by these factors. Since it is possible to determine the reduced amount of bichromate by tannins very accurately, the accuracy of tannin estimation is nearly the same as the official hide powder method.
公益社団法人日本畜産学会の論文