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Appendix B
5/20/2009
12
Corrective action documentation is required for all data outside ± 3σ.
The sample weight of the SRM should mirror that of the unknown
samples (~10 mg).
9.3.3.
The laboratory must use QCS analyses data to assess laboratory
performance against the required accuracy control limits of ± 3σ. The
QCS will be obtained from a source external to the laboratory and
different from the source of calibration standards. The standard
deviation data should be used to establish an on-going precision
statement for the level of concentrations included in the QCS. This data
must be kept on file and be available for review. Values for QCSs
should be plotted with the other control data.
9.4.
Assessing Analyte Recovery
9.4.1.
Percent recoveries cannot be readily obtained from particulate
samples. Consequently, accuracy can only be assessed by analyzing
check standards as samples and quality control samples (QCS).
9.5.
Data Assessment and Acceptance Criteria for Quality Control Measures
INDICATOR
ACCEPTANCE
LIMITS
ACTION
K-factor
KC = 18 to 25 +/- 3σ
18 to 25 µv/µg is
manufacturers
recommended limits.
KN = 7 to 10 µv/µg
7 to 10 µv/µ is
manufactures
recommended limits.
The k-factors must be within the
specified limits or the standard must be
reanalyzed. (see 10.3)
System Blank
BC < 150 µv
BN < 50 µv
If the blank value is greater the
acceptable value, replace the capsules
and rerun the blanks.
External QC (QCS)
start or middle and end
of run cycle
± 3σ
Qualify data if not within acceptance
limits. Rejection criteria for batch.
Standard Reference
Material (SRM) (when
required by data user)
± 3σ
If SRM is outside acceptance limits,
qualify the data for all samples back to
last acceptable SRM or QCS.
Duplicate analysis
(when available)
± 50%
Duplicate sample data must be within ±
50% or be qualified. All duplicates for
this procedure are field duplicates and are
more a measure of field collection and
filtration techniques.
9.6.
Corrective Actions for Out-Of-Control Data
9.6.1.
All samples must be qualified when external QC samples are out of
control.
9.6.2.
All samples between QCSs that are out of control must be qualified.
9.6.3.
All problems with analytical runs must be documented on the bench
sheet.