SELECTIVE LASER ABLATION IONIZATION FOR ION-TRAP MASS-SPECTROMETRY - RESONANT LASER-ABLATION/

Laser ablation provides a clean, broadly applicable ionization source for ion trap mass spectrometry. However, the ion storage capacity of a n ion trap mass spectrometer requires a degree of selectivity in eithe r the ion generation or ion storage process to allow effective interro gation of minority components. This can be accomplished by low-intensi ty irradiation of the sample with laser pulses tuned to a one- or two- photon resonant transition in the analyte of interest. Resonant laser ablation is a multistep process involving evaporation and subsequent i onization of a solid sample component of interest. The leading edge of a tunable laser pulse vaporizes near-surface material, which forms a plume directly above the sample. The trailing edge of the pulse prefer entially excites, and subsequently ionizes, the component that is in r esonance with the incident photons. In this manuscript, we report on t he use of resonant laser ablation with an ion trap mass spectrometer f or high sensitivity, high selectivity generation of analyte ions from a solid sample.