Nuclear power has played an important role in Britain¿s history and is set to play an equally important role in its future. We have recently established a network involving Cardiff University, National Decommissioning Authority, National Nuclear Laboratory and Magnox North to develop rapid, selective methods for the detection and speciation of transuranic radioisotopes in dilute solution. The goal of this project is to develop a range of complexing reagents of differing lipo- and fluorophilicities that display selectivity towards the target analytes, which upon cation binding, partitions into a microemulsion. There the emission properties of the metal cations may be modulated/ enhanced by for example the presence of a micelle/droplet bound sensitizer. This initial experiment is designed to characterise the structure of a model microemulsion in the presence of such complexes.