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Appendix C
5/20/2009
5
3.34
May – Denotes permitted action, but not required action. (NELAC)
3.35
Method Detection Limit (MDL) – The minimum concentration of an
analyte that can be identified, measured, and reported with 98%
confidence that the analyte concentration is greater than zero.
3.36
Must – Denotes a requirement that must be met. (Random House
College Dictionary)
3.37
Non-Dispersive Infrared Detector (NDIR) – The detector found in the
Shimadzu 5000/5000A TOC analyzer. Carbon dioxide is detected.
3.38
Precision – The degree to which a set of observations or measurements
of the same property, obtained under similar conditions, conform to
themselves; a data quality indicator. Precision is usually expressed as
standard deviation, variance or range, in either absolute or relative terms.
(NELAC)
3.39
Preservation – Refrigeration, freezing, and/or reagents added at the time
of sample collection (or later) to maintain the chemical and or biological
integrity of the sample.
3.40
Quality Control Sample (QCS) – A sample of analytes of known and
certified concentrations. The QCS is obtained from a source external to
the laboratory and different from the source of calibration standards. It
is used to check laboratory performance with externally prepared test
materials.
3.41
Run – One sample analysis from start to finish, including printout.
3.42
Run Cycle – Typically a day of operation – the entire analytical
sequence of runs from the first run to the last run and including the
transfer of run cycle data to the disc.
3.43
Sample Volume – Amount of sample injected into the combustion tube.
3.44
Sensitivity – The capability of a test method or instrument to
discriminate between measurement responses representing different
levels (concentrations) of a variable of interest.
3.45
Shall – Denotes a requirement that is mandatory whenever the criterion
for conformance with the specification requires that there be no
deviation. (ANSI)
3.46
Should – Denotes a guideline or recommendation whenever
noncompliance with the specification is permissible. (ANSI)
3.47
Sparge Time – The time required to aerate an acidified sample with ultra
pure air to remove inorganic carbon to determine the concentration of
organic carbon.
3.48
Standard Reference Material (SRM) – Material which has been certified
for specific analytes by a variety of analytical techniques and/or by
numerous laboratories using similar analytical techniques. These may
consist of pure chemicals, buffers, or compositional standards. The
materials are used as an indication of the accuracy of a specific
analytical technique.