Re: Radon in water by LSC (EPA Proposed Method)

[FIELDRW@aol.com]

Franz,

The protocol calls for a water immiscible cocktail.  In my experience with 
water immiscible cocktail (mineral oil), I still had problems with quenching. 
 I have found that some of the iron tends to stay in the oil phase (after the 
initial mixing) and causes quenching.  The protocol recommends fixed windows 
and does not take advantage of the methods you suggested, which I also prefer.

Regards, Bill

College of Public Health
University of Iowa
mailto:bill-field@uiowa.edu  


In a message dated 1/9/00 8:09:31 AM Central Standard Time, schoenho@via.at 
writes:

<< it seems from your
 reply that a water miscible gelforming cocktail is used. I have always used
 the extraction method with a water immiscible cocktail introduced by
 Prichard and Gesell a long time ago. With a water miscible cocktail any
 other radionuclide present would interfere, whereas radon is the only
 radionuclide to be extracted into the water immiscible cocktail. (Rn220
 will decay fast enough not to interfere.) This prevents also quenching by
 for instance iron and manganese, because they will not be extracted.  >>
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