Time-resolved laser-induced fluorescence in total internal reflection mode has been used to monitor the lifetimes of excited species located within the evanescent wave on the aqueous side of the water/1,2-dichloroethane interface, in the presence of varying concentrations of quencher molecules in the adjacent organic phase. The aqueous chromophore used was europium(III), with anthracene being employed as the organic quencher. The kinetic data are obtained from analysis of the relevant mass-transfer regime. The heterogeneous electron transfer rate constant between the two species was found to be 1.9 x 10(-4) m(4) mol(-1) s(-1).