A Catalase Accelerator. 



79 



Abstracts of the Communications, 

 Pacific Coast Branch. 

 Nineteenth Meeting. 



San Francisco, California, February 6, igi8. 



155 (1333) 



Sources of error in the estimation of dextrose by the colorimetric 



picrate method. 



By T. Addis and A. E. Shevky. 



[From the Laboratory of the Medical Division of Stanford University 

 Medical School, San Francisco.] 



A study has been made of the factors involved in the develop- 

 ment of the red-brown color produced on heating solutions con- 

 taining dextrose, picric acid and sodium carbonate. 



The dextrose concentrations chosen corresponded in range to 

 those found in the blood. Temperature levels above 100 0 C. 

 were attained by heating in an autoclave, and the required ac- 

 curacy of temperature control was obtained by means of an elec- 

 tric thermo-regulator. 



The amount of color produced did not vary directly with the 

 amount of sugar present except at a certain definite concentration 

 of sodium carbonate. At low alkali concentrations small amounts 

 of sugar gave relatively less color than large amounts, while at 

 high alkaline concentrations, the reverse was found. The optimum 

 alkali concentration varied with temperature changes. 



With every increase in temperature from 80 to 130 0 C. there 

 was an increase in color production, and at all temperatures the 

 more prolonged the heating, the deeper was the color. 



