The estimation of vitamin B1 in urine

Abstract

A rapid and simple method of estimating vit. B1 as thiochrome is applied to urine. The powdered Decalso used is a more specific adsorbent of the vit. than are activated earths, and gives lower "blanks" and more consistent yields. Fluorescence is measured with the Pulfrich photometer. The method does not estimate low dietary excretions accurately, but is suitable for measuring the response to test-doses, such response being the best test of nutritional level. Measurements of urinary excretion at short intervals after ingestion of 5 mg. of vit. show that the time-lag before excretion depends mainly on the time required for the stomach to empty, and the shortest suitable period of urine collection in saturation tests is 5 hr. The kidney can concentrate vit. B1 from plasma.