To evaluate the necessity for cooling laser-desorbed molecules to obtain molecular ions and minimal fragmentation, mass spectra of a series of methoxybenzenes were measured in two different experimental configurations. In one geometry, laser-desorbed molecules were entrained in a pulsed supersonic jet before ionization. In the other, the molecules were ionized directly after laser desorption. The samples were ionized with laser-generated vacuum ultraviolet radiation in a single-photon process or ultraviolet radiation in a multi-photon process.

Org. Mass Spectrom.

Steenvoorden, R. J. J. M., van der Hage, E. R. E., Boon, J. J., Kistemaker, P. G., & Weeding, T. L. (1994). Investigation of the effects of cooling after laser desorption before post-ionization. Org. Mass Spectrom., 29, 78–84.