Unusual Odd-Electron Fragments from Even-Electron Protonated Prodiginine Precursors Using Positive-Ion Electrospray Tandem Mass Spectrometry

Electron-capture dissociation tandem mass spectrometry.

Electron capture dissociation (ECD) is a new fragmentation technique used in Fourier transform ion cyclotron resonance mass spectrometry and is complementary to traditional tandem mass spectrometry techniques. Disulfide bonds, normally stable to vibrational excitation, are preferentially cleaved in ECD. Fragmentation is fast and specific and labile post-translational modifications and non-coval...

Analysis of catecholamines in urine by positive-ion electrospray tandem mass spectrometry.

BACKGROUND Determination of urinary catecholamines (CATs) is considered important for clinical diagnosis of pheochromocytoma, paraganglioma, and neuroblastoma. The major disadvantages of existing tests include relatively long instrumental analysis time and potential interference from drugs and drug metabolites that are structurally similar to CATs. METHODS CATs were extracted from a 300-micro...

Electrospray and tandem mass spectrometry in biochemistry.

Over the last 20 years, biological MS has changed out of all recognition. This is primarily due to the development in the 1980s of 'soft ionization' methods that permit the ionization and vaporization of large, polar, and thermally labile biomolecules. These developments in ionization mode have driven the design and manufacture of smaller and cheaper mass analysers, making the mass spectrometer...

Electrospray tandem mass spectrometry of 2H-chromenes.

Several 2H-chromenes derived from carbazoles were analyzed by electrospray tandem mass spectrometry. The 2H-chromenes constitute an important class of compounds that exhibit photochromic activity. The fragmentation pathways of the protonated molecular species [M+H]+ were studied, and main fragmentation pathways of these compounds were identified. Fragmentation pathways of [M+D]+ ions were also ...

chromatography–electrospray ionization tandem mass spectrometry