Combined electrophoresis-electrospray interface and method.

System (10) and method for analyzing molecular constituents of a sample (35) of a composition comprising forming a solution of the sample, separating the solution by capillary electrophoresis into an eluent of components separated longitudinally according to their relative electrophoretic mobility, electro-atomizing the eluent to form a charged atomization in which the molecular constituents have a temporary distribution, and detecting or recovering the separated constituents as a function of the temporary distribution in the atomization (64). A first high voltage (for example 5-100 KVDC) is applied to the solution. Atomization is charged by applying a second voltage (for example +/- 2-8KVDC) between the element at the capillary outlet (40) and a cathode (26) spaced at the front of the outlet. A complete electrical circuit (16B) is formed by a conductor (42) which is in direct contact with the eluent at the capillary outlet or by conduction through an electrode flow sheathed around the capillary outlet.