Use of Ascorbic Acid as an Indicator for Heavy Metals

Abstract

MANY enzymes are sensitive to inhibition by heavy metal ions. Because of contamination of water and laboratory reagents, it is often necessary to add a chelating reagent such as EDTA, or a compound with a mercapto group, to react with the offending ion. But too high a concentration of the agent may itself inhibit the enzyme by sequestering cations which are necessary for activation. We report here a method which we have found useful for deciding the proper amount of agent to be added to media or reaction mixtures.