Fwd: RE: I-129 Sources

[Dave Derenzo <dave@uic.edu>]

Correction - In the message below, I think it is a general license, not a 
license exemption.

>Date: Thu, 11 Jan 2001 08:41:28 -0600
>To: radsafe@romulus.ehs.uiuc.edu
>From: Dave Derenzo <dave@uic.edu>
>Subject: RE: I-129 Sources
>
>To all,
>
>David North is correct about I-129.  When used as a mock I-125 standard, a 
>little Am-241 is sometimes mixed in to better emulate the I-125 
>spectrum.  There is an NRC license exemption that reflects 
>this.  Auto-gamma counter manufacturers usually supply mock I-125 
>standards in small test tubes that are similar in size, shape, and 
>counting geometry to the RIA samples that will be analyzed.  Commercial 
>suppliers like Amersham used to sell these also.  Regarding Franz's 
>comment about Ba-133, it is sometimes used as a mock I-131 source, and 
>Co-57 is used to mock Tc-99m.    All of these are common sources used in 
>nuclear medicine (dose calibrator testing, gamma camera peaking, etc) and 
>radioimmunoassay (RIA) labs.  RIA is rapidly being replaced by other 
>techniques.  Here at UIC, what used to be our RIA lab is now called the 
>ligand immunoassay lab and they no longer use radioactive materials.  The 
>only RIA test that is still done uses Co-57 and is sent out to a 
>commercial lab.
>
>Dave Derenzo
>
>At 08:21 AM 1/11/01, you wrote:
>>According to NCRP Report No. 58, I-129 is indeed a gamma-emitter, but the
>>emission is relatively weak (7.5%). Most of the useful photons are x-rays
>>following the prevalent internal conversion after beta-minus decay.
>>
>>David L. North, Sc.M. DABR
>>Associate Physicist
>>Department of Medical Physics
>>Rhode Island Hospital
>>593 Eddy St.
>>Providence, RI 02903
>>ph: (401)444-5961
>>fax: (401)444-4446
>>dnorth@lifespan.org
>>
>>
>> > ----------
>> > From:         Franz Schoenhofer
>> > Reply To:     radsafe@romulus.ehs.uiuc.edu
>> > Sent:         Wednesday, January 10, 2001 18:27
>> > To:   Multiple recipients of list
>> > Subject:      Re: I-129 Sources
>> >
>> >
>> > -----Ursprüngliche Nachricht-----
>> > Von: Perrero, Daren <Perrero@idns.state.il.us>
>> > An: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
>> > Datum: Mittwoch, 10. Jänner 2001 23:05
>> > Betreff: RE: I-129 Sources
>> >
>> >
>> > >I believe what you are referring to is commonly called "a mock iodine"
>> > >source.  The I-129 is configured in such a way that the emitted spectrum
>> > >mimics that of I-125 but has the obvious advantage of the extended half
>> > life
>> > >of I-129.  Most gamma counter equipment vendors would be happy to link
>> > you
>> > >up with direct vendors or may even be able to provide such sources
>> > >themselves.
>> >
>> >
>> > "Mock Iodine" is not I-129, it cannot be, because I-129 is not a
>> > gamma-emitter. Somewhere deeply buried in my brain the information is
>> > stored, maybe it was Ba-133. Daren is right - the vendors can answer this
>> > questions.
>> >
>> > Franz
>> >
>> >
>> >
>> >
>> > ************************************************************************
>> > The RADSAFE Frequently Asked Questions list, archives and subscription
>> > information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html
>> >
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>>The RADSAFE Frequently Asked Questions list, archives and subscription
>>information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html


Dave Derenzo, MPH  (dave@uic.edu)
Associate Director for Radiation Safety
University of Illinois at Chicago
Radiation Safety Section, MC932
820 S. Wood St., Chicago, IL 60612-7314
Voice:(312)996-7429  Fax:(312)996-8776
URL:  http://www.uic.edu/depts/envh

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