Hi Joe,

I strongly recommend treatment of new borosilicate exetainers using 
diluted HNO3. In order to figure out if the cleaning procedure is 
necessary I once compared raw d18O values and d13C values of our 
inhouse carbonate standard using untreated exetainers next to treated 
exetainers that have already been used for years. Untreated exetainers 
clearly gave different results, especially in d13C. Afterwards, I 
cleaned the untreated exetainers and compared them again to the old 
ones. This time, the isotopic data received from both batches was 
indistinguishable.
For the daily purpose, we clean the exetainers with distilled water, 
using a small brush. Afterwards we put them for 2-3 minutes into an 
ultrasonic device and finally dry them at 80°C for 24h. I really can 
recommend the use of a brush. We once did the daily wash without the 
brush for a week or so. We noticed background interferences from 
unspecified substances, exhibiting very long retention times. When we 
used the brush again, these problems disappeared. Probably -on the long 
term- these substances accumulate from the septum.

Best regards
Jens


Dr. Jens Fiebig
Institut für Geowissenschaften
J.W. Goethe Universität
Altenhöferallee 1
60438 Frankfurt am Main
phone: +49-(0)69-79840182
email: [log in to unmask]

On Tuesday, May 22, 2007, at 19:54 Europe/Zagreb, Joe Lambert wrote:

> Hi all,
>
>      We just recently finished the installation of a new Gasbench to 
> our
> Delta Plus.  We'll spend most of our time measuring carbonates.  I
> was wondering how other labs are handling the cleaning of used
> exetainers.  I see that Thermo gives guidelines for cleaning in their
> manual; however, maybe someone has developed a faster/easier method?
>
>      Thermo also recommends that even new unused exetainers should be
> cleaned before measuring carbonates.  Has anyone experienced problems
> if they take the risk and use unwashed new exetainers?
>
> Thanks,
>
> Joe
>
> W. Joe Lambert
> Research Scientist
> Alabama Stable Isotope Laboratory
> University of Alabama
> Geological Sciences
> 202 Bevill Building
> 7th Avenue
> P.O. Box 870338
> Tuscaloosa, AL 35487-0338
> Phone: (205) 348-4404
> Fax: (205) 348-0818
> email: [log in to unmask]
> Visit our web-site: http:www.geo.ua.edu/asil
>