Fluorescent quenching method for determination of trace hydrogen peroxide in rain water

A simple and sensitive fluorescent quenching method for the determination of trace hydrogen peroxide (H2O2) has been proposed to determine hydrogen peroxide in rain water sample. The method is based on the reaction of H2O2 with 3,3'-diethyloxadicarbocyanine iodide (DI) to form a compound which has no fluorescence in acetate buffer solution (pH 3.09). The maximum emission wavelength of the system is located at 604 urn with excitation at 570nm. Under the optimal conditions, the calibration graph was obtained between the quenched fluorescence intensity and hydrogen peroxide concentration in the range of 5.0 x 10(-7) to 9.0 X 10(-4) mol L-1. The proposed method was applied to determine H2O2 in rain water samples, and the result was satisfactory. The mechanism involved in the reaction was also studied. (c) 2006 Elsevier B.V. All rights reserved.