Laser Microprobe Mass Spectrometry LASER MICROPROBE MASS SPECTROMETRY: POSSIBILITIES AND LIMITATIONS

Laser microprobe mass spectrometry (LMMS) employs an intense UV pulse from a focused highpower laser to evaporate and ionize a microvolume (% 1 um3) of solid samples at relatively elevated energy density (106-101’ W cmm2). The ions produced by the interaction of photons with the condensed phase are then mass analyzed in a time-of-flight mass spectrometer and yield a complete mass spectrum on each single laser shot. Depending on the operating conditions, elemental information can be obtained, extensive speciation possibilities for inorganic species are available, and organic compounds can be characterized by means of structurally relevant molecular and fragment ions. Quantitation is difficult, but LMMS remains an excellent tool for qualitative local analysis of microscopic samples, which can be dielectric or conductive. Within the range of microbeam techniques, the method is a valuable complement to the electron and ion microprobe. The idea of combining lasers with MS is not new and has been successfully applied to a variety of analytical purposes, e.g., pyrolysis, classification of complex materials, .soft ionization of organic thermolabile compounds, as an alternative to the spark source mass spectrometer, and for bulk analysis at high power density. The first part of this presentation deals with these types of instrumentation for organic and elemental analysis and surveys the functional principles of the commercially available LMMS equipment: LAMMA 500 and 1000, and the LIMA 2A. The polyvalent nature of LMMS results from the remarkable ease of operation of the instrument under.greatly varying local conditions. The applications are unlimited. Even at the present state of the art, this statement comes very close to the truth. Review of the topics of the contributions at the recently organized triennal users’ meeting yields a vast panorama of the current research in various fields. The workshop’s proceedings’