Dissolved oxygen quantitation in fuel through measurements of dynamically quenched fluorescence lifetimes

An optical method for the quantitation of dissolved molecular oxygen in aviation fuels has been developed to aid the study of thermally induced fuel oxidation. The technique is based on the propensity of dissolved molecular oxygen to quench probe molecule fluorescence excited with a pulsed nitrogen laser. Linear calibration curves based on Stern-Volmer kinetics are generated through measurement of the time-resolved fluorescence signal produced by pyrene doped into aviation fuel at parts per million (ppm) levels. The advantages of nondestructive in-situ monitoring, reduced measurement time, and enhanced capabilities (including spatially resolved and rapidly time-varying measurements) make this optical technique a very attractive complement to current chromatographic and electrochemical methods. Application to flowing-fuel simulators demonstrates the technique.