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A high resolving power multiple reflection matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometer
Author(s) -
Piyadasa C. K. G.,
Håkansson P.,
Ariyaratne T. R.
Publication year - 1999
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(19990415)13:7<620::aid-rcm532>3.0.co;2-f
Subject(s) - chemistry , mass spectrometry , ionization , matrix assisted laser desorption electrospray ionization , time of flight , time of flight mass spectrometry , hybrid mass spectrometer , reflectron , reflection (computer programming) , ambient ionization , spectrometer , matrix (chemical analysis) , analytical chemistry (journal) , selected reaction monitoring , thermal ionization mass spectrometry , electron ionization , optics , chromatography , ion , tandem mass spectrometry , physics , organic chemistry , computer science , programming language
Two electrostatic mirrors, mounted symmetrically on the same optical axis facing each other, are used to increase the time‐of‐flight of molecular ions produced in matrix‐assisted laser desorption/ionization (MALDI). The mirrors, which are used in the non‐compensating mode, are located between a MALDI ion source and a stop detector. The source is operated at 10.5 kV acceleration voltage using the delayed extraction technique. The high voltage for the mirror arrangement is switched on after the desorption event when the molecular ions have drifted into the region between the mirrors. The ions are trapped by successive reflections of the opposite electrostatic fields in the mirrors until the electric fields are switched off. The number of reflections depends on the speed of the ions when they enter the mirror trap and the on‐time of the mirrors. When the electric fields are removed during the motion of the ions towards the stop detector, the ions penetrate the grids of the mirror and reach that detector. The extension of the flight path due to the number of reflections is used to increase the resolving power in time‐of‐flight spectra. Values of 55 000 for substance‐P (MW 1346.7) and 31 000 for bovine insulin (MW 5734) were obtained for single laser shot spectra. Copyright © 1999 John Wiley & Sons, Ltd.