October 4, 2001
Journal Article

Optimal Pressure Conditions for Unbiased External Ion Accumulation in a Two-Dimensional Radio Frequency Quadrupole for Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Abstract

When combined with capillary LC, Fourier transform ion cyclotron resonance mass spectrometry (FTICR) provides a powerful tool for proteomic studies. The sensitivity, dynamic range, and duty cycle provided by FTICR has been shown to be increased by ion trapping and accumulation in a 2D rf-only multipole positioned externally to an FTICR cell. However, it is important that ions be detected across the desired m/z range without a significant bias. In this work we found that pressure inside of the accumulation rf-quadrupole plays an important role in obtaining "unbiased" ion accumulation. Pressure optimization was performed in bothe pulsed and continuous modes. It was found tha unbiased accumulation in a 2D rf-only quadrupole could be achieved in the pressure range of 5 x 10-4 to 5 x 10-3 torr. External ion accumulation performed at the optimal pressure resulted in an increase in both the duty cycle and dynamic range.

Revised: February 7, 2003 | Published: October 4, 2001

Citation

Belov M.E., M.V. Gorshkov, K. Alving, and R.D. Smith. 2001. Optimal Pressure Conditions for Unbiased External Ion Accumulation in a Two-Dimensional Radio Frequency Quadrupole for Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. Rapid Communications in Mass Spectrometry 15, no. 21:1988-1996. PNWD-SA-5453.