Related Experiment Videos
Oxygen isotope corrections for online delta(34)S analysis
Brian Fry1, Steven R Silva, Carol Kendall
1Institute of Pacific Islands Forestry, USDA Forest Service, 1151 Punchbowl St., Room 323, Honolulu, HI 96813, USA. brianfry@fs.fed.us
Rapid Communications in Mass Spectrometry : RCM
|April 12, 2002
Summary
Automated sulfur isotope analysis (delta(34)S) using elemental analyzers coupled with mass spectrometry can be inaccurate. New methods correct for oxygen isotope variations in SO(2), improving sulfur isotope measurements in plants, animals, and soils.
Area of Science:
- Geochemistry
- Analytical Chemistry
- Environmental Science
Background:
- Elemental analyzers coupled with mass spectrometers enable online delta(34)S measurements.
- Current methods show poor reproducibility in oxygen isotope composition of produced SO(2).
- This leads to inaccuracies (1-3 per thousand) in calculated delta(34)S values, especially for samples with high C/S ratios.
Purpose of the Study:
- To develop methods for correcting S isotope values affected by oxygen isotope variations.
- To introduce a new SO(2)-SiO(2) buffering technique to minimize oxygen isotope variations.
- To improve the accuracy of automated delta(34)S measurements in biological and soil samples.
Main Methods:
- Empirical and analytical approaches for correcting S isotope values.
- Development and application of a SO(2)-SiO(2) buffering method.
- Validation of corrected delta(34)S values against accurate measurements.
Main Results:
- Identified and quantified the impact of oxygen isotope variations on delta(34)S measurements.
- Developed correction factors based on empirical and analytical methods.
- Demonstrated the effectiveness of the SO(2)-SiO(2) buffering method in stabilizing oxygen isotopes.
Conclusions:
- Automated delta(34)S measurements require correction for oxygen isotope variations.
- The proposed correction methods and buffering technique significantly improve the accuracy of sulfur isotope analysis.
- These advancements are crucial for reliable isotopic studies in environmental and biological sciences.