Ascorbic acid-induced fluorescence of a noradrenaline oxidation product

Ascorbic acid has been found to induce the fluorescence of an intermediate oxidation product of noradrenaline which is formed in a ferricyanide oxidation. The fluorescence of the product is a function of the ascorbic acid and noradrenaline concentration and at conditions at which the fluorescence of the noradrenaline product is optimal the fluorescence of adrenaline, tested similarly, in negligible. The reaction has a definite pH optimum (pH 6) and the fluorescence of the final product depends on the time of the oxidation. The stability and rate of formation of the noradrenaline product is dependent upon the concentration level of the ascorbic acid and ferricyanide. The reaction shows promise as the basis for a new noradrenaline assay.