The combination of UV-visible absorption spectroscopy and conventional liquid/liquid electrochemistry is applied to study ion transfer at the liquid/liquid interface. Two separate examples of ion transfer are investigated. Results for Ru(bpy)(3)(2+) and the dianionic form of Eosin B transfer from water to 1,2-dichloroethane, obtained using total internal reflection absorption spectroscopy, are presented. The techniques of differential cyclic voltabsorptometry and chronoabsorptometry are investigated and shown both to be specific to individual species and to produce responses analogous to conventional electrochemistry. A simple theory is presented and found to be an accurate description of the spectroscopic methodology.