Sources of Error in Plasma Creatinine Determination

Publisher Website
Google Scholar
Abstract
Creatinine detns. by the Jaffe reaction directly applied to tungstic acid filtrates of plasma have a plus error which may exceed 100%. Among the noncreatinine chromogenic substances responsible for the error glucose is important, but most of the error is due to other chromogens. It does not appear that any modification of the technic for developing color can eliminate the error. Where accuracy is essential, as in measurements of renal creatinine clearances, the creatinine should be separated from the other chromogens. For this purpose adsorption to Lloyd''s reagent is the most practical procedure available at present. The noncreatinine chromogen concn. in plasma is approx. the same in children and adults, whereas the creatinine concn. is very low in young children and increases progressively with age to adult values. To obtain complete recovery of creatinine in tungstic acid filtrates of plasma with subnormal protein concn., the amt. of tungstic acid must be varied in proportion to the protein concn.

This publication has 2 references indexed in Scilit: