A focused laser that ablates a micrometre-scale spot, coupled to a time-of-flight or related mass analyzer, defines laser microprobe mass spectrometry (LMMS, historically LAMMA). The microprobe geometry localizes the desorption and ionization event so that elemental and molecular ions from a selected microscopic volume are recorded [1]. Direct laser desorption from the neat solid may be compared with matrix-assisted desorption from the same microprobe, which changes the ion yield and fragmentation but not the spatial-probe definition [2]. Conceptual boundaries exclude bulk laser-desorption mass spectrometry without spatial selection, secondary-ion microprobes that use an ion beam, and optical laser microprobes that do not mass-analyze the ejecta. Essential features are a diffraction-limited or otherwise focused laser, a viewing system that registers the sampled spot, and a mass analyzer synchronized to the laser pulse [3]. Inorganic deposits and organometallic drugs in tissue have been identified by the same localized ionization, which underscores that the defining object is the microprobe-sampled mass spectrum [4].
- laser microprobe
- LAMMA
- spatially localized ionization
- time-of-flight
Mass Spectrometry Techniques and Applications • Spectroscopy • Chemistry • Physical Sciences
References
- Luc VAN Vaeck; Katrien Poels; Sonja DE Nollin; Adam Hachimi; Renaat Gijbels; LASER MICROPROBE MASS SPECTROMETRY: PRINCIPLE AND APPLICATIONS IN BIOLOGY AND MEDICINE. Cell Biol. Int. 1997, 21, 635-648, 10.1006/cbir.1997.0198.
- Jan Claereboudt; Magda Claeys; Herman Geise; Renaat Gijbels; Akos Vertes; Laser microprobe mass spectrometry of quaternary phosphonium salts: Direct versus matrix-assisted laser desorption. J. Am. Soc. Mass Spectrom. 1993, 4, 798-812, 10.1016/1044-0305(93)80038-z.
- J. Claereboudt; B. de Spiegeleer; E.A. de Bruijn; R. Gijbels; M. Claeys; Structural characterization of cisplatin analogues by fast atom bombardment (FAB) and laser microprobe mass spectrometry (LAMMA). J. Pharm. Biomed. Anal. 1989, 7, 1599-1610, 10.1016/0731-7085(89)80171-2.
- A. H. Verbueken; R. E. Van Grieken; G. J. Paulus; G. A. Verpooten; M. E. De Broe; Laser microprobe mass spectrometry of platinum in dog kidney after cisplatin adminstration. J. Mass Spectrom. 1984, 11, 159-163, 10.1002/bms.1200110404.