 Electrostatic spray ionization

Electrostatic spray ionization (ESI) is a soft ionization technique commonly used in mass spectrometry to produce ions from liquid samples. ESI is particularly effective for analyzing large biomolecules, such as proteins, peptides, and nucleic acids, as well as small organic molecules. In the ESI process, a liquid sample is typically introduced into a nebulizer, where it is atomized into a fine mist of charged droplets through the application of a high voltage.