GAS-PHASE DIAGNOSTICS AND LIF-IMAGING OF 3-HYDROXYPICOLINIC ACID MALDI-MATRIX PLUMES

The first gated laser induced fluorescence (LIF)-imaging and absorptio n spectroscopy have been performed on laser desorbed plumes from organ ic crystals which are commonly used as MALDI !matrix assisted laser de sorption ionization) matrices. These plasma diagnostic techniques, and also ion probe measurements, were employed to investigate the desorbe d products, densities, fractional ionization and velocity distribution s of the plume of 3-hydroxypicolinic acid (3-HPA) under ArF(193 nm)- a nd KrF(238 nm)-laser irradiation. In both cases, gated LIF imaging usi ng 308 nm excitation revealed two plume components: a fast (maximum si milar to 0.1 cm/mu s) low-intensity component which appeal to be 3-HPA fragments, and a slower component of 3-HPA expanding at 0.05 cm/mu s. (C) 1998 Published by Elsevier Science B.V.