[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: High Desolved Solids





> -----Original Message-----
> From:	Lee McCoy [SMTP:mccoy@tcsinternet.net]
> Sent:	Wednesday, April 12, 2000 10:22 AM
> To:	Multiple recipients of list
> Subject:	High Desolved Solids
> 
> Does anyone know of a method for reducing the residual mass of a high =
> dissolved solid sample for  gross alpha beta analysis?=20
> 
	Here's some ideas:

> For the betas, either make a standard with the same mass and geometry of
> the sample or simply reduce the volume you evaporate to make it fit your
> existing mass/efficiency calibration (this will reduce the overall
> sensitivity).
> 
> For alphas, as well as the above, you could plot count rate per ml versus
> volume evaporated, decreasing the amount you evaporate until the plot
> levels off (or you get two consecutive points within uncertainty of each
> other).  At that point you have effectively zero self absorption.  With
> high dissolved solids, the amount will inevitably be very small.
> 
> Alpha/beta discriminating LSC is very good for alphas, almost guaranteed
> 100% counting efficiency.  But I suspect this changes the whole basis of
> what you're doing.
> 
> Eichrom supply an actinide specific chromatography material.  You could
> pass your sample through a column of this, and count it directly by LSC.
> Or oxidise it (very difficult!) and count on planchette.  You'll lose the
> non-actinide alpha emitters doing this.
> 
> Regards
> 
> keith.bradshaw@nnc.co.uk
> 
> 
> 
> 
> 
> 
> 
> 
> END
> 
> 
> 
> 
> 
> END
> 
> 


**********************************************************************
NNC Limited
Booths Hall
Chelford Road
Knutsford
Cheshire
WA16 8QZ

Country of Registration: United Kingdom
Registered Number: 1120437

This email and any files transmitted with it are confidential and 
intended solely for the use of the individual or entity to whom they   
are addressed. If you have received this email in error please notify 
the NNC system manager.
**********************************************************************
************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html