Accelerator Mass Spectrometry sup14/supC Determination in COsub2/sub Produced from Laser Decomposition of Aragonite

Brad E. Rosenheim, Simon R. Thorrold, Mark L. Roberts

Research output: Contribution to journalArticlepeer-review

Abstract

The determination of 14 C in aragonite (CaCO 3 ) decomposed thermally to CO 2 using an yttrium-aluminum-garnet doped neodymium laser is reported. Laser decomposition accelerator mass spectrometry (LD-AMS) measurements reproduce AMS determinations of 14 C from the conventional reaction of aragonite with concentrated phosphoric acid. The lack of significant differences between these sets of measurements indicates that LD-AMS radiocarbon dating can overcome the significant fractionation that has been observed during stable isotope (C and O) laser decomposition analysis of different carbonate minerals. The laser regularly converted nearly 30% of material removed into CO 2 despite it being optimized for ablation, where laser energy breaks material apart rather than chemically altering it. These results illustrate promise for using laser decomposition on the front-end of AMS systems that directly measure CO 2 gas. The feasibility of such measurements depends on (1) the improvement of material removal and/or CO 2 generation efficiency of the laser decomposition system and (2) the ionization efficiency of AMS systems measuring continuously flowing CO 2 .

Original languageAmerican English
JournalRapid Communications in Mass Spectrometry
Volume22
DOIs
StatePublished - Jan 1 2008
Externally publishedYes

Disciplines

  • Life Sciences

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