American Association for Aerosol Research - Abstract Submission

AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA

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Duty Cycle-Based Time of Flight Cross Section Measurement of Large Singly Charged Proteins

PETER T. A. REILLY, Gregory Brabeck, Vivek Jayaram, Rachit Singh, Washington State University

     Abstract Number: 607
     Working Group: Instrumentation and Methods

Abstract
Duty cycle-based digital waveform manipulation is the enabling technology that has extended the working range of time-of-flight mass analyzers up to roughly m/z = 1,000,000. This technology allows millions of massive atmospheric sampled singly-charged ions to be trapped in vacuum at a point just before the end of a linear quadrupole ion trap and then axially ejected on demand in a tightly-collimated temporally-short plug into an awaiting orthogonal acceleration time-of-flight mass spectrometer for highly resolved mass analysis.  The work presented here expands the use of duty cycle-based digital waveform manipulation for cross section measurement to characterize proteins and other large biomolecules and complexes. For this application, duty cycle waveform manipulation is important because it provides a method projecting millions of ions into the collision cell in a tightly focused kinetically controlled plug.  This methodology allows a collection of ions to be separated as a function of size-to-charge ratio with the same experimental setup as was used to measure resolved mass spectra of singly-charged ions.  This work uses ion trajectory simulations to develop the methodology for measurement of protein sizes by time of flight through a low pressure collision cell.  The results were compared with kinetic energy based cross section analysis.