Patent ID: 7204431

Claim:
An electrospray apparatus, comprising: a nozzle defining an exit orifice, an entrance orifice, and a first passage extending from the entrance orifice to the exit orifice, the nozzle defining a nozzle axis; an interface defining an inlet, an outlet, and a second passage extending from the inlet to the outlet, the interface defining an interface axis; the interface disposed such that the inlet is adjacent the exit orifice and the interface axis is in transverse relation to the nozzle axis; wherein an angle formed between the nozzle axis and the interface axis is between about 75 degrees and about 105 degrees, the interface operable to receive a voltage from an interface voltage source; an auxiliary electrode operable to receive a voltage from an auxiliary voltage source, the auxiliary electrode operable to modulate an electric field at the exit orifice and capable of being disposed in positions perpendicular and opposite to the nozzle, the electrospray apparatus operable to define an ion pathway followed by ions enroute from the exit orifice to the inlet, the auxiliary electrode disposed outside the ion pathway.