RE: More on baby teeth

[Franz Schoenhofer <schoenho@via.at>]

At 12:47 03.05.2000 -0500, you wrote:
>I spoke with a radiochemist about a previous post detailing the Sr-90
>analytical method used.  His response was that the separation is not
>specific to Sr, and it's likely that Ra-226 and daughters would be seen as
>well. 

I mentioned this in my response.

 Not only that, but interference will come from both betas and alphas
>in the channels specified, 

I suppose that you mean the interference from other radionuclides which
would not be separated, not only Ra-226 and daughters. Activities of
alpha-emitters comparable to the Sr-90 activity concentration would be
easily detected by checking the pulse-height spectra at the Quantulus,
because the alpha-particles produce distinct "peaks" compared to the betas.
Contribution from other beta-emitters may be less easily detected in the
spectra. Even in the fifties radiochemists knew this, when using
geiger-counters or proportional counters, so the protocols developed and
used are very careful to remove any radionuclides which could disturb. As I
mentioned in my posting, this was not done in the protocol used, unless the
original posting did not contain all the steps of the Sr-90 separation.



as the scintillation photon yield is much lower
>for alphas, bringing the signal into the range of channels indicated.
>Radium levels tend to be a lot lower than 1 pCi/g Ca, but there's a whole
>suite of daughters and also there's variability in the radium content.


Is there anybody who knows about work on Ra-226 in teeth?

Franz


Franz Schoenhofer
Habicherg. 31/7
A-1160 Vienna
Austria
Tel.: +43-1-495 53 08
Fax.: same number
mobile phone: +43-664-338 0 333
e-mail: schoenho@via.at


Office:
Hofrat Dr. Franz Schoenhofer
Federal Ministry of Agriculture, Forestry, Environment and Water Management
Radiation Protection Department (BMLFUW I/8 U)
Radetzkystr. 2
A-1031 Vienna
AUSTRIA

phone: -43-1-71172-4458
fax: -43-1-7122331

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