In relation to the recent postings on organic isotope standards for GC-IRMS,
I would like to bring the following to your attention:
In Sep 1999 a meeting was held at the International Atomic Energy Agency on
Stable Isotope Ratio Measurements by CF/IRMS and Laser Spectroscopy. A
series of review papers was prepared and is presently under review for
publication as an IAEA TECDOC. A short summary and the recommendations of
the working groups on applications in biogeochemistry, in biology and
medicine (labelled compounds), and in atmospheric and hydrological studies
will soon be available on the homepage of the IAEA Isotope Hydrology
Section: http://www.iaea.org/programmes/ripc/ih/index.html following the
links "Meetings / completed" as PDF-document CFIRMS99.pdf (may be you have
to press the reload-button in Acrobat-Reader).
A major part of the meeting dealt with the topic of suitable organic
reference materials for the available modern analytical techniques, their
production and testing, particularly considering homogeneity at small
amounts and compound selective analysis. In this respect a list of possible
candidate materials was prepared with the potential to serve in the future
as international reference materials. Those include two types: 1. bulk
materials for EA (IAEA-CH-3 cellulose (already homogeneity tested),
Thiourea, Methionine, and the existing reference materials IAEA-CH-6
sucrose, IAEA-CH-7 polyethylene foil, NBS22 oil); 2. mixtures of two to four
compounds for GC-IRMS (e.g. N-methyl anthranilic acid esters, C12/C18 fatty
acids methyl esters, GROB-test).
The main challenge would be the careful calibration of those organic
materials versus the internationally adopted scales (VPDB, VSMOW, VCDT,
airN2) and their respective primary reference materials.
Within its existing mandate, the IAEA Isotope Hydrology Laboratory may be
able to coordinate some of these efforts. In order to define priorities and
to form specific groups of laboratories for different reference materials,
we would like to know the following:
1. Which laboratory has already produced materials as stated above and would
be willing to provide them to the IAEA in amounts sufficient for
international distribution as reference materials after careful testing by
2. Which experienced laboratories would participate on a voluntary basis in
testing new materials for suitability as reference materials (tests for
homogeneity at different amount levels, bulk material isotopic composition,
compound specific isotopic composition).
Several participants of the September meeting have already indicated their
willingness to participate in testing new materials (point 2).
In case of your interest and willingness to support these efforts, please
respond directly to the following email address: [log in to unmask] in
order to discuss further details (please do not use the reply-button to
ISOGEOCHEM). I will get back to you after my return to the office at 14.
Head, Isotope Hydrology Laboratory
International Atomic Energy Agency
P.O.Box 100 A-1400 Vienna AUSTRIA
Phone: +43-1-2600-21740/21766 Fax: +43-1-2600-7
e-mail (SMTP) : [log in to unmask]
for ordering reference materials: [log in to unmask]