Electrospray ionization source geometry for mass spectrometry: past, present, and future

The geometry of an electrospray ion source plays important roles in the processes of analyte desolvation, ionization, transportation, and detection in a mass spectrometer. We provide a brief account of the scientific principles involved in developing an electrospray ion source, and in the various geometries used to improve the sensitivity of mass spectrometry. We also present some popular configurations currently available and outline future trends in this research area.