[ RadSafe ] Ge-68 impurity in Ga-68

Ravinkumar Sobnack rvn.sbnck at ntlworld.com
Sat Jun 21 10:16:02 CDT 2008

Dear George

Thanks for the suggestion. A crude Gamma ray spectroscopy with a NaI(Tl)
detector was collected a week or so after the elution when I realised I had
some long lived contaminant in my otherwise 'short-lived' clinical waste
(F-18 and Ga-68)! It is my intention to establish if the radionuclide
impurity remains constant or not with time. If it is constant, it only needs
doing occasionally during the year and one could be reasonably confident of
the impurity level. If it changes from elution to elution, the quality of
the eluate should ideally be established prior to labelling for clinical
use. And that is where I foresee problems. I will have to examine changes in
gamma spectrum to see if the predominantly Ga-68 spectrum looks different
from the delayed Ge-68/Ga-68 equilibrium spectrum.

Kind regards

Ravin Sobnack


-----Original Message-----
From: Geo>K0FF [mailto:GEOelectronics at netscape.com] 
Sent: 21 June 2008 15:03
To: Ravinkumar Sobnack
Subject: Re: [ RadSafe ] Ge-68 impurity in Ga-68


"2. Is there any quick and easy way to check the Ge-68 breakthrough?"


Have you measured the breakthrough by waiting 10 half lives of the daughter 

and then test the residue for Ge-68 using a LEG probe or a Gamma Spec MCA?


George Dowell


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