RF-GD/FTMS: An FTMS system with a lensless external ion source for high resolution elemental mass spectrometry
Year: 1991
Type: conference-paper
Abstract: Two of the major challenges which face the field of elemental mass spectrometry are the development of versatile atomization/ionization sources for direct solids analysis and methods for reducing the impact of isobaric interferences found on commonly employed quadrupole and sector based instruments. The combination of radio frequency glow discharge (RF-GD) sources with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR or FTMS) is one technique which addresses both problems. A demonstration project was conducted at ORNL where an external RF-GD ion source was coupled to a commercial FTMS instrument. The ion transfer system utilized the lensless method developed by Weller, et al for laser desorbed ions. The RF-GD source was contained in a 2.75in. CF cross and separated from the main vacuum system by a skimmer cone. An intermediate differential pumping chamber was separated from the FTMS pumping system. The differential pumping chamber attached directly to the ``analyzer`` flange. Large ion signals could easily be obtained without complex trapping schemes which produced mass spectra with excellent signal-to-noise ratios and resolving powers. Resolutions were limited by the pressure at the analyzer cell. The NIST 1103 Brass sample shows good ratios for the Cu and Zn components. Expected peaks are observed for the Ar+ and ArH+ species. Minor components down to around 1% are observable without any ion ejection techniques. The NIST 1263 Steel sample demonstrates the moderate resolution attainable even with the high pressures in the ICR analyzer cell. This document is an extended abstract with viewgraphs.
Institutions: Clemson University, Oak Ridge National Laboratory
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1593265729