Matrix-assisted laser desoiption ionization

Steiner, W.E. Clowers, B.H. English, W. A. Hill, H.H., Atmospheric pressure matrix-assisted laser desoiption/ionization with analysis by ion mobility time-of-flight mass spectrometry. Rapid Commun. Mass Spectrom. 2004, 18, 882-888. 

Laser Desorption/Ablation Ionization Methods. Matrix-assisted laser desoiption ionization (MALDI) relies on the use of a solid chromophQric matrix, chosen to absorb laser light, which is co-mixed with the analyte (4). Typically, a solution of a few picomoles of analyte is mixed widi a lOO-to-5000 fold excess of the matrix in solution. A few microliters of the resulting solution are deposited on a mass spectrometer solids probe, and the solvent is allowed to evaporate before inserting the probe into the mass spectrometer. When the pulsed laser beam strikes the sample surface in the spectrometer, the sample molecules are desorbedAonized at high efficiency. The various mechanisms for matrix and non-matrix assisted laser desorption have been discussed (5,6). 

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