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Updated: Jun 26, 2026
07:57
Sampling and Pretreatment of Tooth Enamel Carbonate for Stable Carbon and Oxygen Isotope Analysis
Published on: August 15, 2018
Oxygen isotope analysis of phosphate: improved precision using TC/EA CF-IRMS
D F LaPorte1, C Holmden, W P Patterson
1Saskatchewan Isotope Laboratory, Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK, S7N 5E2 Canada. dan.laporte@usask.ca
Journal of Mass Spectrometry : JMS
|January 9, 2009
Summary
This study enhances paleoclimate research by improving oxygen isotope measurements in biogenic apatite. The new method offers greater precision for paleothermometry, making it more accessible to scientists studying past climates.
Area of Science:
- Geochemistry
- Paleoclimatology
- Analytical Chemistry
Background:
- Biogenic apatite oxygen isotopes show promise for paleothermometry due to fossil record abundance and diagenetic resistance.
- Previous limitations in paleothermometry include imprecise isotopic measurements and small sample sizes.
Purpose of the Study:
- To improve the precision of oxygen isotope measurements (delta18O(PO4)) in biogenic apatite.
- To develop a robust methodology for apatite purification and isotopic analysis suitable for small samples.
Main Methods:
- Utilized a modified 'reverse-plumbed' thermal conversion elemental analyzer (TC/EA) coupled to a continuous flow isotope ratio mass spectrometer (CF-IRMS).
- Developed apatite purification chemistry using nitric acid and cation exchange resin, optimized for small samples.
- Implemented a helium stream for gas transfer, improving CO elution peaks.
Main Results:
- Achieved an external precision of +/- 0.15 per thousand (1sigma) for delta18O(PO4) measurements.
- Demonstrated narrower, more symmetrical CO elution peaks with diminished tailing.
- Established that matrix matching for VSMOW scale calibration is unnecessary.
Conclusions:
- The enhanced methodology significantly improves the precision of apatite paleothermometry.
- The refined technique is accessible, requiring only slightly modified, widely available equipment.
- This advancement will broaden the application of apatite paleothermometry in paleoclimate research.
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