Zur photometrischen Bestimmung von Kreatin mit der Diacetyl-Reaktion

Abstract

The diacetyl method for the estimation of creatine was examined to determine the specificity of the reaction and the influence of other substances present in urine. A modified form of the Raaflaub and Abelin method was employed using a lower concentration of NaOH and different time intervals in the photometric determination. A procedure is given for correcting the observed creatine content for the effect of interfering substances in urine some of which promote the reaction while others retard it. Attention is directed to the possibility of false results due to the fact that the diacetyl reaction is specific for the guanidino group in alkaline medium. Substances containing this group may give results indicating apparent creatine excretions of more than 30 mg per day.