Analytical lab performance on spike samples

["Mallon, James" <JMALLO@saix367.sandia.gov>]

  New Thread!

The internal dosimetry group at Sandia is in the process of developing a 
procedure to document the review of lab results for spiked samples.  I have 
reviewed the ANSI N13.30(draft 1994) guidance for performance criteria on QC 
samples.  The ANSI standard identifies numerical criteria for the avg. bias of
a group of spike samples.  This parameter alone is insufficient to evaluate the 
performance of an analytical lab.  Individual sample bias could swing wildly, 
while the average bias is within the -0.25 to +0.50 criteria.

We are thinking of looking at the standard deviation of the bias to provide a 
measure of how the bias is behaving.  So the questions are:

1. Is anyone aware of any formal guidance in this or a related area(e.g. TLD's, 
   radiochemistry)?

2. Has anyone adopted 'rule of thumb' guidance for their own use?

Thanks for the help.

Jamie Mallon

Environmental Dimensions Inc.
Phone 505-844-8287
Fax   505-844-0701
Email JMallo@SAIX367.Sandia.gov

P.S. I'm a Scorpio!