Taking advantage of the electrochemical aspects of electrospray ionization (ESI) sources in positive ionization mode mass spectrometry (MS), aqueous copper complexes are electrogenerated using sacrificial copper electrodes. When using 8-hydroxyquinoline or bathocuproine, two chelating agents for Cu 2+ and Cu + ions, respectively, the electrodissolution of copper leads to the formation of the respective complexes that are then analyzed by MS. This electrochemical generation of copper(I) complexes offers a direct route to synthesize Cu + complexes in aqueous solutions.