Laser microprobe mass spectrometry: principle and applications in biology and medicine.

Laser microprobe mass spectrometry (LMMS) is an interesting technique for micro- and surface analysis. It employs local ionization by a focused laser under high power density conditions and subsequent mass analysis of the generated ions. This paper surveys the main LMMS instruments and their operational principles. Sample preparation is discussed in the context of biological materials. The problem of quantification is addressed. Selected examples show the way that precise information on the molecular composition can be deduced from the detected signals. Both inorganic and organic substances can be identified, even without reference spectra, from in-situ analysis with a lateral resolution in the order of 1 to 5 micrograms.