KINETIC SERUM CREATININE ASSAYS .1. THE ROLE OF VARIOUS FACTORS IN DETERMINING SPECIFICITY

  • 1 January 1980
    • journal article
    • research article
    • Vol. 26  (5) , 551-554
Abstract
The specificity of kinetic methods of analysis was studied with emphasis on creatinine determination. The error contributed by an interferent that reacts with the anlytical reagent and absorbs at the wavelength of analysis is related to the ratio of the equilibrium absorbances of the analyte and interferent, the ratio of the rate constants, the extent of the analytical reaction, and the duration of the measurement. To assess the potential diminution of interference with kinetic methods, the rate constants of several .alpha.-keto acids were determined in the Jaffe reaction. Evaluation of the advantages of various measuring techniques with respect to specificity showed the main factors to be the extent of the analytical reaction and the relative value of the rate constants. Total specificity for creatine appears to be unattainable with currently used kinetic techniques.