Cryoflow: Cryofocusing Nanomole Amounts of CO2, N2, and SO2 from an Elemental Analyzer for Stable Isotopic Analysis
✍ Scribed by Brian Fry; Robert Garritt; Kris Tholke; Christopher Neill; Robert H. Michener; F. J. Mersch; Willi Brand
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 498 KB
- Volume
- 10
- Category
- Article
- ISSN
- 0951-4198
No coin nor oath required. For personal study only.
✦ Synopsis
A manual 'cryoflow' system is d d b e d for measuring C, N and S isotopic compositions of small gas samples in the 10-1000 nmd range. Using a continuous flow system with helium as the carrier gas, sample gases are ix&&d or produced via combustion in an elemental analyzer, purified, separated and collected in separate traps with cryogens, then degassed into a slowly flowing helium stream (1-4 mL/min) for measurement with an isotope rato mass spectrometer. Blanks associated with combustion of organics in an elemental analyzer were 5-24 nmol for N and C, and not detectable for S, so that samples of S O nmol C, N or S muld be routinely analyzd with a precision of better than 0.3% after blank correction. In some cases, slow degassing of sample gases from traps over several minutes gave broad, low-amplitude peaks that yielded high-precision measurements (e.g., <0.05%0 S' C differences between replicates). Work with this manual prototype showed that it is possible to routinely obtain high precision isotope measurements for C, N and S isotopes from the same small sample.