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 the ANSI N13.30 (draft 1994) guidance for performance
criteria on QC samples.  The ANSI standard identifies numerical criteria
for the average bias of a group of spike samples.  This parameter alone
is insufficient to evaluate the performance of an aanalytical 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.  My 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