Dear Francesca,

It would certainly be worth it if as many people would try
such a standard. Wasn't an action from the side of IAEA planned
once, to start an intercallibration on cellulose for establishing
an iternational cellulose standard for 13-C and 18-O?
I havn't heard anything about such an action since! It
would certainly be good and necessary, although I am
aware, that cellulose is not the easiest material to use.
 There are a number of difficulties, e.g. hygro-
scopicity, what kind of cellulose is used etc. Still I am
sure most of us would appreciate a workable standard
of organic mterial, which is good for both 13-C and 18-O.

Rolf



Francesca Smith wrote:

> I was wondering if anyone has measured carbon isotope ratios for an IAEA
> standard: cotton cellulose (IAEA-V-9).  It is a reference material for
> trace and minor elements, but I wondered if anyone had measured its delta
> 13C.  Please respond directly to me, unless you think everyone is
> interested.
>
> Thanks,
> Franesca
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Francesca Smith
>
> Current address:                Department affiliation:
>
> INSTAAR                         Department of Geophysical Sciences
> Campus Box 450                  University of Chicago
> Boulder, CO 80309-0450          5734 S. Ellis Ave
>                                 Chicago, IL 60637
> phone: (303) 492-7808
> fax: (303) 492-6388
>
> email: [log in to unmask]

--
_______________________________________________________

 Dr. Rolf Siegwolf
 Laboratory of Atmospheric Chemistry
 Stable Isotope Research Group / Ecosystem Fluxes
 Paul Scherrer Institute
 CH-5232 Villigen-PSI
 Switzerland
 Phone  : +41 (0)56 310 27 86
 Fax      : +41 (0)56 310 45 25
 e-mail  :  [log in to unmask]
_______________________________________________________