Desorption-chemical ionization mass

Sakushima, A., Nishibe, S., and Brandenberger, H., Negative ion desorption chemical ionization mass spectrometry of flavonoid glycosides, Biomed. Environ. Mass Spectrom., 18, 809, 1989. 

The second example (95a), synthesized by Dalcanale and co-worker181 is asymmetric because of one substituted quinoxaline residue (similar to calix[4]arenes containing one m-substituted phenolic unit). Since the menthyl residue attached to the quinoxaline via an ester function is chiral itself a mixture of the two diastereom-ers was obtained which could be separated by chromatography on silica gel. The subsequent reduction of the ester function in 95a led to enantio-pure (+) and (-) alcohols 95b. The compound 95a was used in host-guest complexation studies182 with benzene, fluorobenzene, 2-fluorotoluene, and isobutane in the gas phase by means of Desorption Chemical Ionization Mass Spectrometry however, studies of chiral recognition have not yet been reported. 

In order to reveal molecular ions, we moved to desorption/chemical ionization mass spectrometry. This direct chemical ionization (DCI), initially described by Me Lafferty in 1973 68 , was widely used and improved recently with the aim of decreasing sharply thermal degradation of samples under vaporization and to extend mass spectrometry capability both to poorly volatile and to very fragile compounds having high molecular masses 69-74). 

ESI-MS/MS Electro spray ionization-tandem mass spectrometry TIS-MS/MS Turbo Ion Spray interface-tandem mass spectrometry EAB-MS Fast atom bombardment-mass spectrometry DCI-MS Desorption chemical ionization-mass spectrometry... 

Desorption/chemical ionization mass spectrometry is a useful technique for the investigation of underivatized polar and involatile compounds such as triterpenoid saponins.162 The cleavage of saponins by anodic oxidation has been investigated,163 as has the glycosidation of triterpenoids.164... 

Vincenti, M., PeUizzetti, E., Guarini, A., and Costanzi, S., Determination of Molecnlar Weight Distributions of polymers by desorption chemical ionization Mass Sp>ectrometry, Anal. Chem., 64, 1879 (1992). 

Chen, G., Cooks, R.G., Jha, S.K., Oupicky D., and Green, M.M., Block Micro-structural Characterization of Copolymers formed from Fluorinated and non-Fluorinated Alkyl Polyisocyanates using Desorption Chemical Ionization Mass Spectrometry Int. Mass Spectrom. Ion Proc, 165/166, 391 (1999). 

Abate, R., Garozzo, D., Rapisardi, R., BaUistreri, A., and Montaudo, G., Sequence Distribution of beta-hydroxyaUcanoate Unit in Bacterial Cojxjlyesters Determined by Desorption Chemical Ionization Mass Sp>ectrometry Rapid Comm. Mass Spectrom, 6, 702 (1992). 

Voisin, D., Smith, J.N., Sakurai, H., McMurry, P.H., Eisele, E.L. (2003) Thermal Desorption Chemical Ionization Mass Spectrometer for Ultrafine Particle Chemical Composition. Aerosol Sci. Technol. 37 471-475. 

Cotter R J 1980 Laser desorption chemical ionization mass spectrometry. Anal Chem 52 1767-1770... 

Electron impact ionization (El) and chemical ionization (Cl) mass spectrometry using a direct insertion probe continue to be used for molecular weight confirmation and identification of purified retinoids. Retinoid fragmentation patterns are useful for identification, especially when mass spectra of unknown compounds are compared to those of reference standards. For example. Buck et al. (284) used El and Cl mass spectrometry with a direct insertion probe to identify retinol as an essential growth factor for the culturing of human B cells, and Lakshman et al. (285,286) used El mass spectrometry to identify retinal O-ethyloxime. Barua (287) reported the desorption chemical ionization mass spectra of retinoyl P-glucuronide after methylation with diazomethane and pertrimethylsilylation. Molecular ions were detected in very low abundance. 

Atmospheric pressure laser-induced acoustic desorption chemical ionization/mass spectrometry (AP-LIAD/CI/MS) for crude oil analysis... 

Helleur, R.J. Thibault, P. Optimization of Pyrolysis-Desorption Chemical Ionization Mass Spectrometry and Tandem Mass Spectrometry of Polysaccharides. Can. J. Chem. 1994, 72, 345-351. 

Vincenti, M. The Renaissance of Desorption Chemical Ionization Mass Spectrometry Characterization of Large InvolatUe Molecules and Nonpolar Polymers. Int. J. Mass Spectrom. 2001, 272,505-518. 

Cullen, W.R. Eigendorf, G.K. Pergan-tis, S.A Desorption Chemical Ionization Mass Spectrometry of T rsenic Compounds Present in the Marine and Terrestrial Environment. Rapid Commun. Mass Spectrom. 1993, 7,33-36. 

Chen, G. Cooks, R.G. Jha,S.K. Green, MM Microstmctnre of THkoxy and 7V1-kyl Substitnted Isocyanate Copolymers Determined by Desorption Chemical Ionization Mass Spectrometry. Anal. Chim. Acta 1997,356, 149-154. 

Desorption chemical ionization mass spectrometry has been used to determine the molecular weight distribution of polystyrene.. The liquid chromatographic behaviour has been studied of polystyrene homopolymers on a C4 pore diameter reversed phase column. Separation was achieved on a molecular weight basis using a tetrahydrofuran-... 

Stillwell, R. N., D. I. Carroll, J. G. Nowlin, and E. C. Horning Formation of Trimethylsilyl Molecular Adduct Ions in Desorption Chemical Ionization Mass Spectrometry of Non-volatile Organic Compounds. Analyt. Chemistry 55, 1313 (1983). 

Bisseret, D. Dessort, Y. Nakatanl and M. Kates, Ammonia desorption chemical ionization mass spectrometry of phosphatldylsulfocholine-phosphatidylcholine mixtures. Chem. Phys. Lipids 36 309 (1985). 

---