DESI Turns 10

Abstract

Desorption electrospray ionization (DESI) was the original ambient sample ionization method for mass spectrometry (Science 2004, DOI: 10.1126/science.1104404). In the 10 years since R. Graham Cooks, Zoltan Takats, and coworkers at Purdue University first described DESI, many other ambient ionization methods have joined it, but none have managed to supplant it. Ambient ionization “represents a huge advance in chemical analysis because it so simplifies sample preparation,” says Richard N. Zare, a chemistry professor at Stanford University. Zare’s lab uses DESI to characterize short-lived reaction intermediates. DESI works by bombarding a sample surface with charged solvent droplets. The droplets in turn desorb charged microdroplets that proceed to fission and evaporate to yield gas-phase ions that are transported into a mass spectrometer. The sample typically is left out in the open and requires little to no sample prep. Mass spec sampling is normally done under vacuum. The proliferation of ambient ionizati...