Dear Jean-Pierre and others,

Although others already gave an answer, I like to add my two pennies.
I did some measurements on NBS-30. The H isotope value I obtained was:
- 66.1 plusminus 0.4 per mil (n = 4), so on a limited amount of
measurements.
This was measured on an extraction line (redesigned by me from a line meant
for water analysis only) where all parts were heated up to the U-reduction
furnace. H2 gas was collected on activated charcoal.
Values are calibrated/corrected on the scale of SLAP-SMOW.
So, accidentally I was pretty close to the given value.

Description of the device I used is in my thesis (and I will include it in
my review part of my books too) - if you like, Jean-Pierre, I can send you a
copy of my thesis.

Best wishes,
Pier

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Dr. Pier A. de Groot
European Commission
Joint Research Centre
Institute for Reference Materials and Measurements (IRMM)
Retieseweg
2440 Geel
Belgium
Tel. +32 (0)14 571 628
Fax +32 (0)14 571 685
e-mail: [log in to unmask]

Visit my WEB-site about my "Handbook of Stable Isotope Analytical
Techniques" at:
http://www.geocities.com/padegroot/index.html
last update: 9 July, 2001.
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-----Original Message-----
From:   Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf
Of Girard Jean-Pierre
Sent:   07 September 2001 17:09
To:     [log in to unmask]
Subject:        delta D of NBS-30

We recently analyzed NBS-30 biotite for hydrogen isotopes for the first time
(we have mainly used it as an oxygen isotope standard in the past) and found
delta D values much lower than the value of -66 per mil given in the IAEA
report on reference materials for stable isotopes (1995, IAEA-TECDOC-825).

Does anyone know of any published DeltaD values for NBS-30 other than that
in the IAEA report ?

Also, if anyone is (has been) using NBS-30 routinely as a standard for H
isotopes, we would be interested to know what kind of values and
repeatability you get.


Jean-Pierre

***************************************************************
Jean-Pierre GIRARD
BRGM  - ANA/ISO
3 avenue Cl. Guillemin, BP 6009
45060 Orléans cedex 2, France
Tel:+33-(0)2-38643215 ;  Fax:+33-(0)2-38643925
E-mail: [log in to unmask]  ; Web: www.brgm.fr
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