G.G. Hatch Stable Isotope Laboratory

25 Templeton Street
Advanced Research Complex
Faculty of Science
University of Ottawa
Ottawa, ON Canada
K1N 6N5
Attn: P. Middlestead

Find us at:
25 Templeton Street
Advanced Research Complex (ARC)
Room 426

For all inquiries click here.

Paul Middlestead, Lab Manager
Tel: (613) 562-5800
ext. 6839 (office)
ext. 6836 (lab)

Dr. Ian Clark, Director

Organic Solids Analysis Techniques


Carbon and nitrogen isotopes techniques

Organic solids are weighed into tin capsules. Calibrated internal standards are prepared with every batch of samples for normalization of the data. In general, 100µg of N are required for analysis. The carbon can be diluted with helium when there is higher %C than %N as is usually the case. Elemental analysis must be performed first if the quantities of carbon and/or nitrogen in a sample are unknown.

The isotopic composition of organic carbon and nitrogen is determined by the analysis of CO2 and N2 produced by combustion on an Elementar Isotope Cube Elemental Analyser followed by "trap and purge" separation and on-line analysis by continuous-flow with a DeltaPlus Advantage isotope ratio mass spectrometer coupled with a ConFlo III. 

For difficult materials such as soils or filters, up to 200mg of material can be handled in a single sample with at least double that amount of tungstic oxide (WO3).

The routine precision of the analyses is 0.20‰.


  • Pella, E., (1990) Elemental organic analysis, parts 1-2. American Laboratory, Feb. & Aug.
  • Instruction Manuals for the elementar VarioEL III or the CE Instruments EA1110, and the Thermo Finnigan DeltaPlus or DeltaPlus Advantage.
  • Brodie, Chris R., Leng, Melanie J., Casford, James S.L., Kendrick, Christopher P., Lloyd, Jeremy M., Yongqiang, Zong, Bird, Michael I., Evidence for bias in C and N concentrations and δ13C composition of terrestrial and aquatic organic materials due to pre-analysis acid preparation methods, Chemical Geology (2011), doi: 10.1016/j.chemgeo.2011.01.007
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Last updated: 2015.02.04