We have examined the nucleation of chemically generated nitrogen gas bubbles in microheterogeneous systems, using optical microscopy on a model system consisting of a single liquid-liquid interface. Results clearly show that bubble nucleation occurs in both the aqueous and on phases, despite the nitrogen production reaction being a purely aqueous phase process. A theoretical model is developed which describes the time evolution of the nitrogen concentration profile, and this reveals that bubbles in the on are a result of homogeneous nucleation of dissolved N-2 transported across the interface into a (supersaturated) diffusion layer. We further show that bubble nucleation in the on can be inhibited or eliminated by adding water-soluble surfactants, which facilitates aqueous phase bubble nucleation and then acts as highly effective nitrogen sinks, severely reducing the flux of dissolved gas across the water-on interface.