In this study, the in-flow demulsification of a water-in-toluene emulsion by an alternating electric field was investigated. A fluorocarbon tube, chosen for its flexibility and resistance to toluene, was positioned between copper electrodes attached to a voltage supply and a wave generator. With this design, it was possible to apply a strong electric field of 1000 kV/m as the emulsion was not in direct contact with the electrodes. The demulsification rate increased on increasing the frequency of the alternating electric field up to similar to 100 Hz, and a square wave was more effective than a sine wave at low frequencies. Furthermore, the demulsification rate increased on increasing the content of the organic phase and intensity of the electric field. We investigated the effects of an electrolyte dissolved in the aqueous phase, and found that it promoted demulsification in relation to the valence of the cation used. Additionally, demulsification was strongly affected by the ionic strength of the aqueous phase. Our results show that demulsification by the application of an alternating electric field can be very useful in the continuous flow treatment of extraction mixtures in organic synthesis. (C) 2015 Elsevier B.V. All rights reserved.