European Journal of Mass Spectrometry - Abstract of Letter: High-energy electron transfer dissociation using a tandem time-of- flight mass spectrometer with an electrospray ionization source

Letter: High-energy electron transfer dissociation using a tandem time-of- flight mass spectrometer with an electrospray ionization source

Hirofumi Nagao,^a,* Shuichi Shimma,^b Shigeo Hayakawa,^c Kunio Awazu,^a Michisato Toyoda^d
^aDivision of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka Universty, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. E-mail: nagao@mass.phys.sci.osaka-u.ac.jp
^bRenovation Center of Instruments for Science Education and Technology, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
^cDepartment of Chemistry, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka, 599-8531, Japan
^dDepartment of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan

A tandem time-of-flight (ToF) mass spectrometer with an electrospray ionization (ESI) ion source (“ESI- TOF/quad”) was enhanced to perform high-energy electron transfer dissociation (ETD) experiments. Specifically, the collision cell for rare gas targets of ESI- TOF/quadTOF was replaced with one for alkali metal targets. High-energy ETD spectra were obtained of doubly protonated polypeptides and a phosphopeptide using a Cs target. Peaks due to several c- and z-type fragment ions formed by the high-energy ETD process were clearly observed in all cases. These results demonstrate that high-energy ETD can be performed using ESI-TOF/quadTOF.

Keywords: ESI, potential-lift, tandem time-of-flight mass spectrometer, high-energy ETD, alkali metal target, quadratic-field ion mirror