Effect of Various Protein Precipitants on Recoveries of Creatinine Added to Plasma

摘要

The effect of various types of protein precipitation procedures upon the recovery of creatinine added to blood has been investigated. Complete recoveries of creatinine were obtained with tungstic acid, trichloroacetic acid, perchloric acid, and cadmium hydroxide types of protein precipitation. Incomplete recoveries were obtained with Ba(OH)2 + ZnSO4 and NaOH + ZnSO4 types of protein precipitation.A comparison was made of the normal values for creatine and creatinine in whole blood and plasma obtained by the picric acid and by the o -nitrobenzaldehyde methods of analysis. The o -nitrobenzaldehyde values were 97, 43, 40, and 80 per cent of the picric acid values for whole-blood creatine, whole-blood creatinine, plasma creatine, and plasma creatinine, respectively.