A dual detector Fourier transform electrostatic linear ion trap utilizing in-trap potential lift

作者：Dziekonski Eric T; Santini Robert E; McLuckey Scott A^*

来源：International Journal of Mass Spectrometry, 2016, 405: 1-8.

DOI：10.1016/j.ijms.2016.05.010

• Electrostatic linear ion trap
• Fourier transform
• Multiple detectors
• Mass analyzer

Ion capture from an external nano-electrospray ionization source in an electrostatic linear ion trap has been effected by in-trap potential lift so as to avoid a time-dependent frequency drift of trapped ions. This phenomenon was observed when using mirror switching for capturing ions and compromised the mass resolution when using Fourier transform techniques for mass determination. A dual image charge detection approach was also implemented to compensate for losses in mass resolution associated with increasing the length of the electrostatic trap to accommodate the lift region. The potential lift approach for ion capture led to no detectable frequency shifts, thereby enabling the achievement of pressure limited theoretical resolutions. For example, a resolution of roughly 11,000 M/Delta M FWHM was observed for a carborane anion population of average m/z= 520 at a transient length of 125 ms. The use of the dual detector approach led to an increase (similar to 12%) in the ion frequencies used for mass analysis, which more than compensated for the effect of increasing the length of the electrostatic trap. Although the implementation of the potential lift approach and dual detectors were successful in their objectives, these changes resulted in a narrower m/z range for a single ion injection event relative to mirror switching. Furthermore, the dual detector approach resulted in a higher noise floor and a more complicated frequency spectrum due to asymmetries in the electric fields of the ion trap.

• 出版日期2016-7-10