Current Organic Chemistry - Volume 7, Issue 15, 2003

Mass spectrometry has made outstanding progress in recent decades. By awarding the Nobel Prize for 2002 for chemistry to Drs. John B. Fenn and Koichi Tanaka, the scientific community has recognized the revolution mass spectrometry has made in identifying and analyzing large biological molecules. Therefore a dedicated issue on current topics in mass spectrometry is very appropriate. While writing this preface, I realized Read More

Tandem mass spectrometry (MS / MS) is a well-established technique for determining biomolecular primary sequences. The main advantages of MS / MS analysis compared to more traditional sequencing techniques are speed of analysis, sensitivity, high resolution and high mass accuracy. Currently, the highest performance (highest resolution, highest mass accuracy) mass analyzer is the Fourier transform ion cyclotron res Read More

High precision isotope ratio mass spectrometry (IRMS) enables the detection of variability in isotope abundance due to natural processes. IRMS instruments are highly specialized for the analysis of 13 C / 12 C, 2 H / 1 H, 15 N / 14 N, 18 O / 16 O, and 34 S / 32 S via analysis gases CO 2, H 2, N 2, and SO 2 using a tight electron impact ion source, high transmission magnetic sector, and multiple collectors, delivering relative stand Read More

In principle, Franck-Condon one-electron oxidation of an anion of known bond connectivity in a collision cell of a mass spectrometer may give the corresponding neutral. This neutral may be transmitted to a second collision cell in which it may be ionised. In order to be detected in the second cell, a neutral must be stable for the 10 -6 sec between formation in one collision cell and ionisation in the second. If the neutrals are co Read More

Radial cations of unsaturated organic hydrocarbons are reactive intermediates of many important chemical reactions. In particular, the rate constants of the reactions of these electron deficient species with electron rich reactants are increased by several orders of magnitude compared to the reaction between neutral partners. This effects has been termed “electron hole catalysis”. To get insight into the mechanism(s) of Read More

The possibility to study large molecules and their non-covalent interactions by mass spectrometry (MS) has opened novel ways to investigate protein folding and binding reactions. MS can be applied to protein conformational studies in two conceptually different ways. One approach uses MS to monitor mass changes produced by conformation-sensitive reactions, such as hydrogen / deuterium (H / D) exchange, alkylation a Read More

Flavin-derived compounds such as riboflavin, riboflavin 5'-phosphate (flavin mononucleotide, FMN) and flavin-adenine dinucleotide (FAD), under matrix-assisted laser desorption ionization (MALDI) and fast atom bombardment (FAB) conditions produce unprecedented reduced species that can be attributed to [M+2H]+. and [M+3H]+ in addition to the anticipated [M+H]+ ions. On the other hand, electrospray ionization (ESI) con Read More

Electrospray ionization (ESI) is a soft ionization technique well suited for producing gas phase ions of biological macromolecules. The use of ESI when combined with collision-induced dissociation and mass analysis can give structural information about biomolecules. Traditionally, collisional fragmentation is carried out by tandem mass spectrometry. Several commercially available instruments permit tandem mass spectrom Read More