PH AND CONCENTRATION RESPONSE SURFACES FOR THE LUMINOL-H2O2 ELECTROGENERATED CHEMILUMINESCENCE REACTION

A response surface for the luminol-H2O2 electrogenerated chemiluminesc ence (ECL) reaction is constructed by systematically altering the pH a nd reagent concentration while determining luminol or H2O2. Ranges cov ered are 0.5 through 500 mu M H2O2 and pH 7 through 10 for luminol det erminations and 0.1 through 1000 mu M luminol and pH 7 through 10 for H2O2 determinations. At a given luminol or H2O2 concentration the ECL response surface with respect to pH and reagent concentration is essen tially identical in general shape to the response surface observed at any other concentration. With this information one can predict the cha nge in ECL response between any two sets of conditions or maintain the same ECL response with two sets of conditions if appropriately chosen . In general, monotonically sloping contours are observed such that as the pH or the luminol or H2O2, concentration is increased, there is a corresponding increase in ECL response.