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NELAC Accrediting Body Fee Structures Comparison

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					       Data Qualifiers:
How Do You Qualify Your Data?

Use and Application of Data Qualifiers According to
              Chapter 62-160, F.A.C.




                     Betsy Kent
Reedy Creek Improvement District, Lake Buena Vista, Florida
Precision

The sample and the duplicate values
are > LOD and < LOQ and qualified
as < LOQ.
The RPD for these values is > UCL.
Do you qualify the data for precision
failure?
Do you use the RPD in the statistical
calculation of limits?
Precision

The sample value is slightly greater
than the LOQ and the duplicate value
is between the LOD and LOQ.
The RPD for these values is > UCL.
Do you qualify the data?
Do you use the RPD in the statistical
calculation of limits?
  Precision
The sample value is between the LOD
and LOQ and qualified as such. The
duplicate value is < LOD (ND).
Do you calculate a RPD?
If yes, what value do you use for the non-
detect?
Do you qualify the data?
If calculated, do you use the RPD in the
statistical calculation of limits?
Precision
The LOD is 1.0 ppm.
The LOQ is 4.0 ppm.
The sample value is 4.0 ppm
The duplicate value is 4.9 ppm
The RPD UCL is 20.0.
The RPD for these values is 20.2.
Do you qualify the Data?
  Precision

Does your laboratory have a documented
procedure to use a factor to determine
when to evaluate data for precision?
Example: If concentrations < 5x LOD
then RPD is NA.
Is this procedure acceptable under the
NELAC 2003 Standard? FDEP 62-160?
 Precision
 NELAC 2003 Standard
D.1.1.3.2
a) Purpose: matrix duplicates are defined
as replicate aliquots of the same sample
taken through the entire analytical
procedure. The results from this analysis
indicate the precision of the results from
the specific sample using the selected
method. The matrix duplicate provides a
usable measure of precision only when
target analytes are found in the sample
chosen for duplication.
 Precision
 NELAC 2003 Standard
D.1.1.3.2
d) Evaluation Criteria and Corrective
Action: The results from matrix duplicates
are primarily designed to assess the
precision of analytical results in a given
matrix and are expressed as relative
percent difference (RPD) or other
statistical treatment (e.g., absolute
differences). The laboratory shall
document the calculation for relative
percent difference or other statistical
treatments.
Precision
NELAC 2003 Standard
D.1.1.3.2
d cont.) Results are compared to the
acceptance criteria as published in the
mandated test method. Where there are
no established criteria, the laboratory
shall determine internal criteria and
document the method used to establish
the limits. For matrix duplicate results
outside established criteria corrective
actions shall be documented or the data
reported with appropriate data
qualifying codes.
 Accuracy

The MS is within %R control limits.
The MSD is outside %R control limits.
The MS/MSD RPD is within RPD
control limits.

Do you qualify the data for accuracy
failure?
 Accuracy
 NELAC 2003 Standard
Program Policy and Structure -
Appendix A - Glossary (Effective
July 1, 2005)
Matrix Spike Duplicate (spiked
sample or fortified sample
duplicate): a second replicate matrix
spike prepared in the laboratory and
analyzed to obtain a measure of the
precision of the recovery of each
analyte. (QAMS)
 Accuracy
The MS and MSD are outside %R
control limits.
The LCS and all associated method QC
is within control limits.

Do you qualify the data for accuracy
failure citing suspect matrix
interference? How do you determine
that matrix interference was the cause?
   Accuracy
The %R’s for MS and MSD are < LCL.
The data is qualified for accuracy failure.
Do you include information of low bias
recovery on the data report?

The %R’s for MS and MSD are > UCL.
The data is qualified for accuracy failure.
Do you include information of high bias
recovery on the data report?
  Accuracy
EPA 8260 –Analyze sample with 4
surrogate standards
1 out of 4 surrogates is outside %R limits.

Do you qualify data results?
All compounds? Sub-set of compounds?
Do you include information on bias on
the data report?
 Accuracy
EPA 8270 – Analyze sample with 3 BN
and 3 Acid surrogate standards
1 out of 3 BN surrogates is outside %R
limits.

Do you qualify data results?
All compounds? All BN compounds?
Sub-set BN compounds?
Do you include information on bias on
the data report?
Data Reports
Where Do You Place the P&A
Qualifiers?
On the Data Report with the
sample value?

On the Quality Control Report with
the RPD and/or %R?

In the Case Narrative?

In Sample Comments?
Data Reports
Where Do You Place the P&A
Qualifiers?


How do you address data received
from a sub-contract laboratory that
does not include the data qualifier(s)
next to the sample value?
Thank you


Betsy Kent
RCID Environmental Services
betsy.kent@rcid.dst.fl.us

				
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