A rapid and reproducible method is described for measurement of urea in biological materials (after deproteinisation) and in serum (without deproteinisation). Urea is colorimetrically determined with diacetyl monoxime and thiosemicarbazide in the presence of sulphuric acid, phosphoric acid and ferric chloride. The sensitivity of the colorimetric reaction and stability of the colour are enhanced...

In recent years, a series of thiamine derivatives has been synthesized and many investigations have been made both chemically and medically. Allithiamine, a S-alkyl thiamine derivative, was studied in the previous pa per (1) and was found to have polarographically a similar behavior to thia mine. In the present experiment, polarographic investigations on diacetyl thiamine (DAT) and dibenzoylthi...