A novel microfluidic approach for the quantification ofreaction kinetics is presented. A three-dimensional finitedifference numerical simulation was developed in orderto extract quantitative kinetic information from fluorescence lifetime imaging experimental data. This approachwas first utilized for the study of a fluorescence quenchingreaction within a microchannel; the lifetime of a fluorophore was used to map the diffusion of a quencher acrossthe microchannel. The approach was then applied to amore complex chemical reaction between a fluorescentamine and an acid chloride, via numerical simulation thebimolecular rate constant for this reaction was obtained.