Isotopic metrology of carbon dioxide. II. Effects of ion source materials, 
conductance, emission, and accelerating voltage on dual-inlet cross 
contamination

Verkouteren, R. M.; Assonov, S.; Klinedinst, D. B.; Brand, W. A.

Item

ITEM ACTIONSEXPORT

Add to Basket

Local TagsRelease HistoryDetailsSummary

Released

Journal Article

Isotopic metrology of carbon dioxide. II. Effects of ion source materials, conductance, emission, and accelerating voltage on dual-inlet cross contamination

MPS-Authors

/persons/resource/persons62345

Brand, W. A.
Service Facility Stable Isotope/Gas Analytics, Dr. W. A. Brand, Max Planck Institute for Biogeochemistry, Max Planck Society;

External Resource

No external resources are shared

Fulltext (restricted access)

There are currently no full texts shared for your IP range.

Fulltext (public)

There are no public fulltexts stored in PuRe

Supplementary Material (public)

There is no public supplementary material available

Citation

Verkouteren, R. M., Assonov, S., Klinedinst, D. B., & Brand, W. A. (2003). Isotopic metrology of carbon dioxide. II. Effects of ion source materials, conductance, emission, and accelerating voltage on dual-inlet cross contamination. Rapid Communications in Mass Spectrometry, 17(8), 777-782.

Cite as: https://hdl.handle.net/11858/00-001M-0000-000E-D131-4

Abstract

We report high-precision isotopic carbon dioxide measurements, made before and after ion source modification to gas isotope ratio mass spectrometry (IRMS) instruments. Measurement protocols were designed to explore the effects of ion source material substitution, source conductance, inlet pressure, electron emission, acceleration potential, and inlet changeover equilibration time. After modification of the IRMS instruments at the National Institute of Standards and Technology (NIST) and the Max-Planck-Institute for Chemistry (MPI-Mainz), immediate changes were observed. At NIST, measurements were no longer sensitive to inlet equilibration times greater than 15s, and different settings of ion source conductance resulted in delta(13)C shifts of about 0.04parts per thousand per 10parts per thousand measurement difference between sample and reference, a five-fold improvement. No significant changes in machine performance were observed after a month of use. After a year, performance had degraded slightly, but was controlled by ion source cleaning and the use of low-energy ion acceleration to minimize sputtering. At MPI-Mainz, results were very similar. We report cross-contamination coefficients measured since 1996, and discuss the role of adsorption, ion implantation, and sputtering on cross contamination in mass spectrometry systems. We recommend that users of high-precision IRMS instruments test for and minimize the effects described. Published in 2003 by John Wiley Sons, Ltd.