Myung, Sunnie, Lee, Young Jin, Moon, Myeong Hee, Taraszka, John, Sowell, Rena, Koeniger, Stormy, Hilderbrand, Amy E., Valentine, Stephen J., Cherbas, Lucy, Cherbas, Peter, Kaufmann, Thomas C., Miller, David F., Mechref, Yehia, Novotny, Milos V., Ewing, Michael A., Sporleder, C. Ray, and Clemmer, David E.
A linear octopole trap interface for an ion mobility time-of-fright mass spectrometer has been developed for focusing and accumulating continuous beams of ions produced by electrospray ionization. The interface improves experimental efficiencies by factors of ~50-200 compared with an analogous configuration that utilizes a three-dimensional Paul geometry trap (Hoaglund-Hyzer, C. S.; Lee, Y. J.; Counterman, A. E.; Clemmer, D. E. Anal. Chem. 2002, 74, 992-1006). With these improvements, it is possible to record nested drift (flight) time distributions for complex mixtures in fractions of a second. We demonstrate the approach for several well-defined peptide mixtures and an assessment of the detection limits is given. Additionally, we demonstrate the utility of the approach in the field of proteomics by an on-line, three-dimensional nano-LC-ion mobility-TOF separation of tryptic peptides from the Drosophila proteome.