RE: High Desolved Solids

["Bradshaw, Keith" <Keith.Bradshaw@nnc.co.uk>]

> -----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
> 
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> END
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> 


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