Jump to main content
Jump to site search

Issue 12, 2017
Previous Article Next Article

Unique capabilities of AC frequency scanning and its implementation on a Mars Organic Molecule Analyzer linear ion trap

Author affiliations

Abstract

A limitation of conventional quadrupole ion trap scan modes which use rf amplitude control for mass scanning is that, in order to detect a subset of an ion population, the rest of the ion population must also be interrogated. That is, ions cannot be detected out of order; they must be detected in order of either increasing or decreasing mass-to-charge (m/z). However, an ion trap operated in the ac frequency scan mode, where the rf amplitude is kept constant and instead the ac frequency is used for mass-selective operations, has no such limitation because any variation in the ac frequency affects only the subset of ions whose secular frequencies match the perturbation frequency. Hence, an ion trap operated in the ac frequency scan mode can perform any arbitrary mass scan, as well as a sequence of scans, using a single ion injection; we demonstrate both capabilities here. Combining these two capabilities, we demonstrate the acquisition of a full mass spectrum, a product ion spectrum, and a second generation product ion spectrum using a single ion injection event. We further demonstrate a “segmented scan” in which different mass ranges are interrogated at different rf amplitudes in order to improve resolution over a portion of the mass range, and a “periodic scan” in which ions are continuously introduced into the ion trap to achieve a nearly 100% duty cycle. These unique scan modes, along with other characteristics of ac frequency scanning, are particularly appropriate for miniature ion trap mass spectrometers. Hence, implementation of ac frequency scanning on a prototype of the Mars Organic Molecule Analyzer mass spectrometer is also described.

Graphical abstract: Unique capabilities of AC frequency scanning and its implementation on a Mars Organic Molecule Analyzer linear ion trap

Back to tab navigation

Publication details

The article was received on 20 Apr 2017, accepted on 20 May 2017 and first published on 22 May 2017


Article type: Paper
DOI: 10.1039/C7AN00664K
Citation: Analyst, 2017,142, 2109-2117
  •   Request permissions

    Unique capabilities of AC frequency scanning and its implementation on a Mars Organic Molecule Analyzer linear ion trap

    D. T. Snyder, D. A. Kaplan, R. M. Danell, F. H. W. van Amerom, V. T. Pinnick, W. B. Brinckerhoff, P. R. Mahaffy and R. G. Cooks, Analyst, 2017, 142, 2109
    DOI: 10.1039/C7AN00664K

Search articles by author

Spotlight

Advertisements