[ RadSafe ] Re: Trying to track down for purchase a ScintrexUA3Uranium Fluorimeter

[Bob Shannon]

For the last year, I have been trying to get a response from Scintrex about
whether they are still in the fluorimetry business.  After 'one last try', I
just heard from them that they no longer produce or support the UA-3.

 

The most widely distributed similar instrument is the Kinetic
Phosphorescence Analyzer (KPA) manufactured by Chemchek (Richland WA)
http://www.chemchek.com/. This instrument is somewhat more stable and
specific than the UA-3 and, if used properly, provides rapid, sensitive and
accurate total U results in water and several other matrices.

 

I very much support Dan McCarn's assessment that ICP-MS is 2007 state of the
art. It provides sensitivity, and (my standard disclaimer) if operated
properly, is capable of providing isotopic U-238 and U-235 results used for
accurate determination of U enrichment. 

 

Given the overhead involved in procuring, maintaining and operating ICP-MS,
however, it would appear that for smaller-scale operations, the KPA may have
a market niche.  It is also an approved method for US EPA drinking water
uranium determinations (ASTM D5174).

 

 

Bob Shannon 

Quality Radioanalytical Support, LLC

303-432-1137

 

 

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On Behalf
Of Dan W McCarn
Sent: Sunday, June 17, 2007 8:37 AM
To: 'Mark Sonter'
Cc: radsafe at radlab.nl; Bruce Thomson
Subject: RE: [ RadSafe ] Re: Trying to track down for purchase a
ScintrexUA3Uranium Fluorimeter

 

 

Hi - 

 

The old UA3's suffered greatly from the limited life of the UV laser and

quite variable UV light output.  They are not as easy to operate as your

friend might remember from the "good old days".  Because of significant

baseline drift, I used the method of standard additions (with a

micropipette) to calibrate the instrument "on the fly" and got very good

results.

 

Dr Bruce Thomson, Chair of the Environmental Engineering Department of the

University of New Mexico in Albuquerque has one of these instruments, but it

would require at least $10,000 to repair it.  New instruments cost about

$50,000 or more from Scintrex.  I took a close look at that instrument to

determine what it would take to repair it several years ago.  He might be

willing to sell it to you.

 

There are alternatives.  A more conventional spectrophotometer also has a

similar MDL and PQL in the high ppt.  I priced one built by a Russian firm

in St. Petersburg several years ago at about $10-$15,000.  The UV light

source could be replaced at a low cost.  The following hyperlink discusses

some of the more common analytical methods:

 

 http://www.atsdr.cdc.gov/toxprofiles/tp150-c6.pdf

 

Inductively coupled plasma-mass spectrometry (ICP-MS) is the standard lab

method today.

 

Good Luck!

 

Dan ii

Dan W McCarn, Geologist

Albuquerque & Houston