ELECTROCHEMICAL QUANTIFICATION OF PHENOL USING MUSHROOM TYROSINASE - DETERMINATION OF THE KINETIC-PARAMETERS OF THE ENZYME

This article presents a sensitive electroanalytical method for the det ermination of phenol in the presence of mushroom tyrosinase as well as a simple methodology: to evaluate the kinetic parameters of this enzy me. The quantification is performed at low potential from the oxidatio n current of pyrocatechol that is formed by the action of mushroom tyr osinase in air-saturated solutions. Any electrochemically activated gl assy carbon electrode is used. The course of the reaction is followed by cyclic voltammetry. A linear relationship holds up to 9.0 x 10(-5) M, a detection limit is 4.6 x 10(-7) hi with a precision of 3.2% and a correlation coefficient of 0.997. Kinetic parameters evaluated from t he same experiments are V-max = 0.005 mu mol of pyrocatechol produced per minute and K-M = 2.0 x 10(-4) M.