Study of bio-molecules in an Electrostatic Ion Beam Trap

Recently a new setup for mass spectrometry of large bio-molecules was built in the laboratory. The idea of this system is coupling of an electrospray ion source with an electrostatic ion beam trap. Electrospray is now a well established technique to produce ionic bio-molecules in the gas phase, such as amino acids, peptides etc. High voltage is applied to a liquid supplied through a fine needle forming a Taylor cone, which emits a liquid jet (see figure 1). These lead to the formation of small highly charged droplets which are radially dispresed due to Coulomb repultion. In 2002 a Nobel prize was awarded to J. Fenn for the development of electrospay ionization for the analysis of biomolecules. The molecule species (mass and charge) could be selected using an RF quadrupole ion guide (shown in Figure 2) located after the ion source. A Paul trap located downstream is used to continueously accumulate the molecular ions. The selected molecules are injected into the electrostatic ion beam trap and may be studied through interactions with laser light, scattering with rest gas inside the trap and more.

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The project is carried out in our lab in collaboration with the group of Prof. Michal Neeman from the  biological regulation department .

More literature on the subject:

  1. J. B. Fenn, M. Mann, C. K. Meng, S. F. Wong, and C. M. Whitehouse, Science 246, 64 (1989).

  2. D. Zajfman, Y. Rudich, I. Sagi, D. Strasser, D. W. Savin, S. Goldberg, M. Rappaport, O. Heber, International Journal of Mass Spectrometry 229, 55-60 (2003).

  3. A. V. Tolmachev, I. V. Chernushevich, A. F. Dodonov, K.G. Standing, Nuclear Instruments and Methods in Physics Research B 124, 112-119 (1997)