Dear Steve,
At 17:45 07.10.98 +0100, you wrote:
>Dear List Members,
>
>I'm interested in the possibility of measuring the H, C and O isotope
>composition of cellulose and wonder if anybody is in a position to help
>me with a couple of queries.
>
>(1) Would anybody be able to supply me with a copy of the following
>item- Edwards, T.W.D. & Elgood, R. 1992. Extraction of sediment
>cellulose for oxygen and carbon isotope analysis. Technical Proceedings
>28.0, Environmental Isotope Laboratory, University of Waterloo, Ontario.
>9pp.
>
>(2) Is anybody aware of an alternative to the benzene-methanol
>extraction for the preparation of cellulose extracts. I'm not too happy
>about the benzene (unless there's no alternative).
>
>Cheers,
>
>Steve Crowley
>
>Stable Isotope Laboratory
>University of Liverpool
At the University of Bern (Dept of Climate and Environmental Physics) we
use a 1:1 toluene-ethanol mixture (5-7 hours in a soxhlett distilation
apparatus) to extract the resins and lipids from fine grounded
(approximately 0.1mm) wood. This is the first step we use in order to
"produce" alpha-cellulose out of our wood samples. The next steps involve
NaClO2, acetic acid and NaOH.
Actually I don't know whether it functions for extraction of sediment
cellulose, but for wood samples it functions very well. And toluene-ethanol
are certainly less toxic than benzene-methanol.
Hope it will help. If you want more details about our technique, let me know.
Cheers,
Silvio
-------------------------------------------
Silvio Borella /\
Klima- und Umweltphysik //\\
Phys. Inst., Uni Bern ///\\\
Sidlerstr. 15 ///\\\
CH-3012 Bern ////\\\\
Switzerland ///\\\
//¦¦\\
Tel.: 031/631'44'70 ¦¦
Fax.: 031/631'44'05 ¦¦
e-mail: [log in to unmask] ********
http://www.climate.unibe.ch/~borella
-------------------------------------------
„He who joyfully marches to music in rank and file has already earned my
contempt. He has been given a large brain by mistake, since for him the
spinal cord would fully suffice. This disgrace to civilization should be
done away with at once. Heroism at command, senseless brutality, deplorable
love-of-country stance, how violently I hate all this, how dispicable and
ignoble war is; I would rather be torn to shreds than be part of so base an
action!
It is my conviction that killing under the cloak of war is nothing but an
act of murder."
Albert Einstein
-------------------------------------------
|