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Post‐source Decay and Delayed Extraction in Matrix‐assisted Laser Desorption/Ionization‐Reflectron Time‐of‐Flight Mass Spectrometry. Are There Trade‐offs?
Author(s) -
Kaufmann Raimund,
Chaurand Pierre,
Kirsch Dieter,
Spengler Bernhard
Publication year - 1996
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/(sici)1097-0231(19960731)10:10<1199::aid-rcm643>3.0.co;2-f
Subject(s) - reflectron , chemistry , mass spectrometry , ion , ionization , analytical chemistry (journal) , mass spectrum , ion source , metastability , time of flight mass spectrometry , desorption , extraction (chemistry) , atomic physics , chromatography , physics , organic chemistry , adsorption
By the incorporation of delayed extraction (DE) into matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry a dramatic improvement of performance with respect to sensitivity, mass resolution and mass accuracy of precursor ions up to ⪅10 kDa has been achieved. Since DE reduces collisional in‐source activation to a large extent, the rate of subsequent metastable decay is considerably reduced. Results are presented which demonstrate that under DE the loss of total post‐source decay (PSD) fragment ion yield can be as large as one order of magnitude but that, in terms of sensitivity, part of this loss is balanced by a better S/N ratio which results from a significantly improved mass resolution of the PSD fragment ions ( M /Δ M up to 1800 compared with M /Δ M =200–500 under prompt extraction). While this compensatory effect is true for the middle to high mass range of PSD fragment ions, it gradually vanishes towards the low mass end of the PSD mass scale where, in the case of linear peptides some important information (immonium ions) is lost. It appears, however, that in the majority of practical PSD work, DE improves the qualty of the PSD spectra and that high energy collisional post‐source activation can compensate for the occasional loss of analytical information.