Journal
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
Volume 32, Issue 3, Pages 579-586Publisher
ROYAL SOC CHEMISTRY
DOI: 10.1039/c6ja00278a
Keywords
-
Categories
Funding
- Department of Earth Sciences of ETH Zurich
- SNF [200021-146651, 200021-155923]
- ETH Zurich Postdoctoral Fellowship Program
Ask authors/readers for more resources
We document recent advances in analytical protocols that employ 10(13) Omega resistors in the Faraday cup amplifier feedback loop for high-precision U-Pb geochronology by isotope dilution thermal ionisation mass spectrometry (ID-TIMS). We present a direct comparison of high-precision U-Pb data obtained using different detector systems, including dynamic peak hopping on a secondary electron multiplier and static multicollection routines that use 10(13) Omega resistors in the amplifier feedback loop. The high-ohmic resistors also allow the precise and accurate measurement of the minor (272)(UO2) isotopologues (mostly (UOO)-U-238-O-18-O-16) in a static multicollection routine, which permits precise and accurate determination of the O-18/O-16 ratio of UO2 molecules during the U-isotope ratio measurement without compromising signal intensity on the more abundant UO2 isotopologues. This enables the precise determination of U abundances in zircons by isotope dilution with within-run correction of isobaric interferences from the minor UO2 isotopologues, thereby eliminating one of the major sources of uncertainty in ultra-highprecision U-Pb data sets. This approach permits the determination of single U-Pb dates with uncertainties <0.2 parts per thousand and corresponding weighted mean dates with uncertainties <0.1 parts per thousand (n similar to 6 to 10). Furthermore, the ability to use different combinations of detector setups for the same analysis within the same mass spectrometer allows for direct comparison of independently calibrated detector systems.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available