Vasicek LA, Ledvina AR, Shaw J, Griep-Raming J, Westphall MS, Coon JJ, Brodbelt JS.
J Am Soc Mass Spectrom. 2011 Jun;22(6):1105-8.
We modified a dual pressure linear ion trap Orbitrap to permit infrared multiphoton dissociation (IRMPD) in the higher energy collisional dissociation (HCD) cell for high resolution analysis. A number of parameters, including the pressures of the C-trap and HCD cell, the radio frequency (rf) amplitude applied to the C-trap, and the HCD DC offset, were evaluated to optimize IRMPD efficiency and maintain a high signal-to-noise ratio. IRMPD was utilized for characterization of phosphopeptides, supercharged peptides, and N-terminal modified peptides, as well as for top-down protein analysis. The high resolution and high mass accuracy capabilities of the Orbitrap analyzer facilitated confident assignment of product ions arising from IRMPD.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3202985/pdf/nihms296259.pdf
Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, TX 78712, USA.