File:Electrospray ionization.jpg

Summary
The API electrospray ionization source on an Agilent 6340 ion trap. The solvent is 50% methanol, 50% water, and is being sprayed at 0.5 mL/min.

The conical piece at the right with two holes is the inlet shield leading to the mass spectrometer. The upper port sprays a stream of nitrogen, and the larger lower port is the inlet to the capillary. Another stream of nitrogen comes from a concentric tube within the spray needle assembly, which surrounds the solvent spray as it emerges from the inner spray needle.

Photo by Jonathan Hilmer.