Methods for assessing the level of nutrition of the human subject. Estimation of vitamin B1 in urine by the thiochrome test

Abstract

IN earlier work [Harris & Leong, 1936; Harris et al. 1938] it was shown that the extent of the body's "reserves" of vitamin B1 might be measured by means of a test on the urine, similar in principle to that previously introduced for vitamin C [Harris et al. 1933; Harris & Ray, 1935]. The urinary output was found to depend on the past intake, being negligible in beri-beri or in "conditioned" deficiencies of vitamin B1 and being lowered in certain other abnormal states.To simplify the procedure, several investigators [e.g.

Effect of diets rich in protein upon rats deprived of vitamin B1

“…Examination of casein for vitamin B1. In order to determine whether the action of the casein in preventing loss of weight and bradyeardia was due to its possible contamination with vitamin B1, the casein was analysed for the vitamin according to the method of Wang & Harris [1939] and Harris & Wang [1941]. 50 g. of the light-white casein were heated on a water-bath with about 500 ml.…”

The estimation of vitamin B1 in urine

“…isoButanol (B.D.H. Laboratory Reagent) may be used as received, but gives a lower "blank" when redistilled, as stated by Wang & Harris [1939]. The pure solvent may be recovered after the analysis by fractionation of the neutralized wet alcohol mixture.…”

Laboratory Findings in Fibrositis

“…The process used was essentially that of Wang and Harris,8 in which the amount of the vitamin excreted in the urine is estimated after the removal of the preformed thiochrome by extraction with iso-butanol. A small amount of the extracted sample is oxidised with potassium ferricyanide in alkaline solution and the thiochrome extracted with iso-butanol, which is then washed with water and compared visually against a standard solution of pure vitamin B, under an ultraviolet lamp.…”