Authors: Sasa M Miladinovic Scott A Robotham Charles L Wilkins
Publish Date: 2008/08/26
Volume: 392, Issue: 4, Pages: 585-594
Abstract
A wide mass range trapping experiment using internal source matrixassisted laser desorption–Fourier transform mass spectrometry MALDI–FTMS was evaluated In this method the front trap plate potential is ramped up and the rear trap plate potential is simultaneously decreased using a cubic cell to trap ions over a wide range of masstocharge ratios To apply this to MS/MS experiments a second ion ejection procedure would remove unwanted ions with the selected remaining ions then fragmented by collisioninduced dissociation In measurements using a 72T unshielded magnet presented here an approximately equimolar mixture of a set of polyethylene glycol PEG species for the ramped measurements had peak areas of 10101010 as did the previously described integral method which gave peak areas of 10111010 in good agreement with the known composition of the samples deposited on the MALDI probe tip Comparative MALDI–TOF in reflectron mode results were of similar quality for the equimolar mixture giving a ratio of 10101209 All methods failed to varying degrees when individual PEG compositions of the trial mixture were changed However the previously described integral method showed relatively better results for all but the PEG 8000 doubled mixture
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