A laser microprobe mass spectrometer (LMMS), also laser microprobe mass analyzer (LAMMA), laser ionization mass spectrometer (LIMS), or laser ionization mass analyzer (LIMA)[1] is a mass spectrometer that uses a focused laser for microanalysis.[2][3][4] It employs local ionization by a pulsed laser and subsequent mass analysis of the generated ions.
Methods
editIn laser microprobe mass analysis, a highly focused laser beam is pulsed on a micro sample usually with a volume of approximately 1 microliter. The resulting ions generated by this laser are then analyzed with time-of-flight mass spectrometry to give composition, concentration, and in the case of organic molecules structural information.
Unlike other methods of microprobe analysis which involve ions or electrons, the LMMS microproble fires an ultraviolet pulse in order to create ions.
Advantages
editLMMS is relatively simple to operate compared to other methods. Furthermore, its strengths include its ability to analyze biological materials to detect certain compounds (such as metals or organic materials).
Sample preparation
editLAMMA is particular about the sample which is used. The sample must be small and thin. Ionization of too much material results in a large microplasma whose time spread and ion energy distribution entering the mass spectrometer can result in undesired peak deformation.
See also
editReferences
edit- ^ Sabine Becker (28 February 2008). Inorganic Mass Spectrometry: Principles and Applications. John Wiley & Sons. pp. 154–. ISBN 978-0-470-51720-8.
- ^ Hillenkamp, F.; Unsöld, E.; Kaufmann, R.; Nitsche, R. (1975). "A high-sensitivity laser microprobe mass analyzer". Applied Physics. 8 (4): 341–348. Bibcode:1975ApPhy...8..341H. doi:10.1007/BF00898368. ISSN 0340-3793.
- ^ Denoyer, Eric.; Van Grieken, Rene.; Adams, Fred.; Natusch, David F. S. (1982). "Laser microprobe mass spectrometry. 1. Basic principles and performance characteristics". Analytical Chemistry. 54 (1): 26–41. doi:10.1021/ac00238a001. ISSN 0003-2700.
- ^ Van Vaeck, L (1997). "LASER MICROPROBE MASS SPECTROMETRY: PRINCIPLE AND APPLICATIONS IN BIOLOGY AND MEDICINE". Cell Biology International. 21 (10): 635–648. doi:10.1006/cbir.1997.0198. ISSN 1065-6995.