Imaging of Vapor Plumes Produced by Matrix Assisted Laser Desorption: A Plume Sharpening Effect

Abstract

The first gated imaging of both light matrix molecule and heavy biomolecule vapor expansion during matrix assisted laser desorption and ionization is reported, revealing a plume sharpening effect. Laser induced fluorescence imaging of dye-tagged DNasethinspthinspI proteins shows that these heavy molecules (30thinsp000thinspthinspDa) propagate within a very narrow angular distribution compared to that of the 3-HPA matrix (139thinspthinspDa). A special solution of the gas dynamic equations is developed to describe the 3D coexpansion of heavy and light plume components. {copyright} {ital 1999} {ital The American Physical Society}