MALDI desorption ionization mass

The most discriminating technique for proving the identity and purity of analyte peak of a chromatogram, especially for analyzing biological samples and natural products, is by using online LC-UV/MS or GC-MS/FTIR methods [15]. Alternatively, one could use a combination of TLC and MS, where direct determination on the TLC plates is made by matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) [16]. 

Many diseases are characterized by the expression of specific proteins1 in some cases, malignant cells yield unique protein profiles when total cellular protein extracts are analyzed by proteomic methods such as two-dimensional gel electrophoresis or matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS).2 High-throughput proteomic studies may be useful to differentiate normal cells from cancer cells, to identify and define the use of biomarkers for specific cancers, and to characterize the clinical course of disease. Proteomics can also be used to isolate and characterize potential drug targets and to evaluate the efficacy of treatments. 

Other MS based analytical approaches have occasionally been applied to ancient resin samples, in particular for paint varnishes. Such techniques include FABS (fast atom bombardment mass spectrometry) [35], MALDI (matrix assisted laser desorption-ionization mass spectrometry) and GALDI (graphite assisted laser desorption-ionization mass spectrometry) [36 38]. 

Site has good software subdivision devoted to matrix-assisted laser desorption/ ionization mass spectrometric imaging (MALDI-MSI, also termed imaging MS or MS imaging). 

Matrix-assisted laser desorption-ionization mass spectrometry (MALDI-MS), 78 774... 

Lang SR, Staudenmann W, James P, Manz HJ, Kessler R, Galli B, Moser HP, Rummelt A, Merkle HP (1996) Proteolysis of human calcitonin in excised bovine nasal mucosa elucidation of the metabolic pathway by liquid secondary ionization mass spectrometry (LSIMS) and matrix assisted laser desorption ionization mass spectrometry (MALDI). Pharm Res 13 1679-1685. 

Matrix-assisted laser desorption ionization mass spectrometry (MALDI) uses a matrix, typically of aromatic acids, whose molecular weight is similar to those of typical metabolites and thus disallows the mass spectrometric measurement of the latter. 

Mark-Honwink eqnation Relates limiting viscosity number (LVN) to molecular weight LVN = KM . matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) MS in which the sample is placed in a matrix that contains a strong ultraviolet (LTV) absorber chosen to match the UV absorption of the laser, which allows the molecules to become volatilized with minimal fragmentation. 

The exception to this is the application of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). In 1981, Barber and Liu and coworkers independently introduced the concept of employing MALDI where the absorption of the matrix is chosen to coincide with the wavelength of the employed laser to assist in the volatilization of materials. In 1988, Tanaka, Hillenkamp, and coworkers employed the laser as the energy source, giving birth to MALDI-MS. 

Two recently developed mass spectrometric techniques have had a major impact on the analysis of large biomolecules matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and electrospray ionization mass spectrometry (ESI-MS). MALDI-MS was first introduced by Karas and Hillenkamp66 and Tanaka et al.61 in 1988 and has experienced an exponential development. It has become a widespread soft ionization technique for bioorganic samples, especially large biomolecules. Fenn and co-workers68 first published the successful soft ionization technique for... 

Figure 5-5. A. MALDI mass spectrum of the anthocyanin pigments in the grape variety Marechal Foch. This figure is from the article Matrix-assisted laser desorption ionization mass spectrometry analysis of grape anthocyanins , Am. J. Enol. Vitic. 50 199-203 by Sugui, J. A., Wood, K. V., Yang, Z., Bonham, C. C. and Nicholson, R. L. 1999. Reprinted by permission of the American Society for Enology and Viticulture. B. MALDI mass spectrum of grape anthocyanins acquired on a MALDI mass spectrometer with delayed extraction capabilities. Peak identities are discussed in the text.

The low volatility of ILs makes them useful as solvents working under high vacuum, and together with their more amorphous solid analogs they are convenient in matrix-assisted laser-desorption/ ionization-mass spectroscopy (MALDI-MS) analysis.103104... 

Hahner S, Ludemann HC, Kirpekar F, Nordhoff E, Roepstorff P, Galla HJ, Hillenkamp F. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI) of endonuclease digests of RNA. Nucleic Acids Res 1997 25 1957-1964. 

Development of a wide range of Surface MALDI mass spectrometry methods12 opens new possibilities in MS investigations of bio-interfacial phenomena, summarized recently as biological surface science . Thus, matrix-assisted laser desorption ionization mass spectrometry, and its variants, hold promise to help clarify the mechanisms of bio-activity of silica-based nanocomposites. 

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