Re: Cr-51 counting

["Schoenhofer" <schoenho@via.at>]

Schoenhofer
Habichergasse 31/7
A-1160 Wien
AUSTRIA
Tel./Fax: +43-1-4955308
Mobiltel.: +43-664-3380333
e-mail: schoenho@via.at
-----Ursprüngliche Nachricht-----
Von: Knapp, Timothy M. <timothy_knapp@merck.com>
An: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
Datum: Dienstag, 28. April 1998 16:40
Betreff: Cr-51 counting


>Greetings all,
>Looking for opinions on the "best" way to detect Cr-51 on smears and as a
>liquid sample, both with handheld instruments and bench top instruments
(LSC
>and Gamma counter)? I'm looking, specifically, for any thoughts on self
>attenuation within these types of samples and how that may affect counting.
>Any input would be appreciated.
>
>Standard disclaimers as usual
>
>Thanks
>
>Tim Knapp
>-----------------------------------------------------------------------

Tim,

Until now I only came across Cr-51 in river water many years ago. We used to
take water samples from a small river running to Austria from former
Czechoslovakia. We used 20 to 40 l samples and evaporated them. We measured
them by high resolution gamma spectrometry (Germanium detectors). We were
always surprised by the relatively high concentrations and could not imagine
how so many nuclear medicine tests with Cr-51 could be performed along this
small river, until we learned by chance that it was used as a tracer for
hydrological research on that river. This might answer your question, how to
detect it - use gamma-spectrometry. Nevertheless, LSC must be a very good,
if not better alternative, because of the higher efficiency! Sorry, I do not
have Cr-51 at hand, otherwise I would have told you the answer tomorrow.

Best regards,

Franz