Minnesota Administrative Rules
Agency 144 - Health Department
Chapter 4740 - LABORATORIES; ACCREDITATION REQUIREMENTS
Part 4740.2100 - QUALITY CONTROL CRITERIA FOR CHEMISTRY EXCEPT RADIOCHEMISTRY
Universal Citation: MN Rules 4740.2100
Current through Register Vol. 49, No. 13, September 23, 2024
Subpart 1. Scope.
This part applies to laboratories performing testing under the inorganic chemistry, metals, volatile organic compounds, and other organic compounds test categories unless otherwise indicated. All requirements in this part must be incorporated into the laboratory's procedures unless otherwise directed by the approved method. The quality control requirements specified by the laboratory's standard operating procedures manual must be followed. All quality control measures must be assessed and evaluated on an ongoing basis and quality control acceptance criteria must be used to determine the validity of the data.
Subp. 2. Method blanks.
A. The method
blank must be processed along with and under the same conditions as the
associated samples to include all steps of the analytical procedure.
B. Each contaminated method blank must be
critically evaluated as to the nature of the interference and the effect on the
analysis of each sample within the batch. The source of contamination must be
investigated and measures taken to minimize or eliminate the problem. Affected
samples must be reprocessed or data must be appropriately qualified if:
(1) the concentration of a targeted analyte
in the blank is at or above the reporting limit as established by the test
method or by regulation and is greater than one-tenth of the amount measured in
any sample; or
(2) the blank
contamination otherwise affects the sample results according to test method
requirements or the individual project data quality objectives.
C. Procedures must be in place to
determine whether a method blank is contaminated. Any affected samples
associated with a contaminated method blank must be reprocessed for analysis or
the results reported with appropriate data qualifying codes.
D. The method blank must be analyzed at a
minimum of one per batch.
Subp. 3. Laboratory control sample.
A. A laboratory control sample (LCS) must be
used to evaluate the performance of the total analytical system, including all
preparation and analysis steps. Results of the LCS must be compared to
established criteria and, if found to be outside of established criteria, must
indicate that the analytical system is "out of control." Any affected samples
associated with an out-of-control LCS must be reprocessed for reanalysis or the
results reported with appropriate data qualifying codes.
B. A laboratory control sample must be
analyzed at a minimum of one per preparation batch except:
(1) analytes for which no spiking solutions
are available; or
(2) in instances
for which no separate preparation method is used, such as volatiles in water,
the batch must be defined as environmental samples that are analyzed together
with the same method and personnel, using the same lots of reagents, not to
exceed the analysis of 20 environmental samples.
C. All analyte concentrations must be within
the calibration range of the instrument calibration. The components to be
spiked must be as specified by the permit, program, or rule requirement. In the
absence of permit, program, rule, or method requirements, the laboratory must
spike as follows:
(1) for those components
that interfere with an accurate assessment, such as spiking simultaneously with
technical chlordane, toxaphene, and PCBs, the spike must be chosen that
represents the chemistries and elution patterns of the components to be
reported; and
(2) the number of
analytes selected is dependent on the number of analytes reported. The analytes
selected for the spiking solution must be representative of all analytes
reported. The following criteria must be used for determining the minimum
number of analytes to be spiked:
(a) for
methods that include one to ten analytes, spike all components;
(b) for methods that include 11 to 20
analytes, spike at least ten components or 80 percent of the analytes,
whichever is greater; and
(c) for
methods with more than 20 analytes, spike at least 16 components.
D. The results of the
analytes included in the LCS are calculated in percent recovery or measure that
allows comparison to established acceptance criteria. The laboratory must
document the calculation. The individual LCS is compared to the acceptance
criteria as published in the approved method. When there are no established
criteria, the laboratory must determine its own criteria and document the
method used to establish the limits or utilize client-specified assessment
criteria within a permit, program, or rule requirement.
E. A laboratory control sample that is
determined to be within the criteria effectively establishes that the
analytical system is in control and validates system performance for the
samples in the associated batch. Samples analyzed along with a LCS determined
to be "out of control" must be considered suspect. The samples must be
reprocessed and reanalyzed or the data reported with appropriate data
qualifying codes.
Subp. 4. Matrix spike and matrix spike duplicates.
A. The frequency of the analysis of matrix
spikes and matrix spike duplicates must be determined as part of a systematic
planning process or as specified by the required approved method. The matrix
spikes must be prepared from samples contained in the batch.
B. For a matrix spike, the components to be
spiked must be as specified by the approved method or permit, program, or rule
requirement. In the absence of specified spiking components, the laboratory may
follow client instructions and then must document its criteria for quality
control. In the absence of client instruction, the laboratory must spike as
follows:
(1) for those components that
interfere with an accurate assessment, such as spiking simultaneously with
technical chlordane, toxaphene, and PCBs, the spike must be chosen that
represents the chemistries and elution patterns of the components to be
reported; and
(2) the number of
analytes selected is dependent on the number of analytes reported. The analytes
selected for the spiking solution must be representative of all analytes
reported. The following criteria must be used for determining the minimum
number of analytes to be spiked:
(a) for
methods that include one to ten analytes, spike all components;
(b) for methods that include 11 to 20
analytes, spike at least ten or 80 percent of the analytes, whichever is
greater; and
(c) for methods with
more than 20 analytes, spike at least 16 components.
C. The results from matrix spikes
and matrix spike duplicates must be expressed as percent recovery, relative
percent difference, absolute difference, or other measure. Results of matrix
spikes and matrix spike duplicates must be compared to the acceptance criteria
as published in the approved method. When there are no established criteria,
the laboratory must determine its own criteria and document the procedure used
to establish the limits or utilize client-specified assessment criteria within
a permit, program, or rule requirement.
Subp. 5. Surrogate spikes.
A. This subpart applies to the analysis of
organic compounds.
B. Except when
the matrix precludes their use, or when not available, surrogate compounds must
be added to all samples, standards, and blanks for all appropriate test
methods.
C. Surrogate compounds
must be chosen to represent the various chemistries of the analytes in the
method. When specified, the surrogates mandated in the method must be
used.
D. The results from surrogate
spikes must be expressed as percent recovery. Results of surrogate spikes must
be compared to the acceptance criteria as published in the approved method.
When there are no established criteria, the laboratory must determine its own
criteria and document the method used to establish the limits or utilize
client-specified assessment criteria within a permit, program, or rule
requirement.
Subp. 6. Internal standards.
A. When
internal standards are recommended or required by the test method, such as mass
spectrometry techniques, a laboratory must add the internal standards to all
samples, standards, blanks, and quality control samples before
analysis.
B. When specified in the
test method, a laboratory must use the internal standards mandated in the test
method. If internal standards are not recommended in the method, then the
analyst must select one or more internal standards that are similar in
analytical behavior to the compounds of interest and not expected to be found
in the samples otherwise.
C. A
laboratory must monitor and document the results from analysis of internal
standards.
D. Results of internal
standards must be compared to the acceptance criteria as published in the
approved method. When there are no established criteria, the laboratory must
determine its own criteria and document the procedure used to establish the
limits or utilize client-specified assessment criteria within a permit,
program, or rule requirement.
Subp. 7. Detection limits.
A. A laboratory must utilize a test method
that provides a detection limit that is appropriate and relevant for the
intended use of the data. The detection limit, such as method detection limit
(MDL), must be determined by the protocol in the approved method or applicable
regulation. If the protocol for determining detection limits is not specified,
the selection of the procedure must reflect instrument limitations and the
intended application of the test method.
B. The commissioner shall not require a
detection limit study for any component for which spiking solutions or quality
control samples are not available.
C. A laboratory must initially determine the
detection limit for the compounds of interest in each test method in a matrix
in which there are not target analytes or interferences at a concentration that
would impact the results or the laboratory must determine the detection limit
in the matrix of interest.
D. A
laboratory must determine the detection limits each time there is a change in
the test method that may affect how the test is performed or when a change in
instrumentation occurs that affects the sensitivity of the analysis.
E. A laboratory must include all sample
processing steps of the analytical method in the determination of the detection
limit.
F. A laboratory must
document all procedures used to determine the detection limit, including the
matrix type of the sample and all supporting data.
Subp. 8. Reporting limits.
A. A laboratory must document all procedures
used to determine the reporting limit.
B. A laboratory must establish reporting
limits for each field of testing. The reporting limits must be greater than
detection limits.
C. A laboratory
must verify the reporting limit each time the instrument is calibrated, or
monthly at a minimum. The laboratory must analyze a verification standard with
a concentration at or below the reporting limit. The percent recovery of the
standard must fall within plus or minus 40 percent of the true value.
D. If the percent recovery of the reporting
limit verification standard is outside the acceptance criteria, a laboratory
must elevate the reporting limit for the associated samples to the
concentration of the lowest point, above the zero blank, that meets the
acceptance criteria defined in item C. The laboratory must report all samples
analyzed after the failed reporting limit check using the elevated reporting
limit until a new calibration curve and reporting limit verification standard
meet the acceptance criteria.
Subp. 9. Selectivity.
A .
Absolute retention time and relative retention time aid in identifying
components in chromatographic analyses and evaluating the effectiveness of a
chromatographic medium to separate constituents. A laboratory must develop and
document acceptance criteria for retention time windows if the acceptance
criteria are not specified in the approved method.
B. A confirmation must be performed to verify
the compound identification when positive results are detected on drinking
water. The confirmations must be performed on organic tests, such as
pesticides, herbicides, or acid-extract-able compounds, or when recommended by
the analytical test method, except when the analysis involves the use of a mass
spectrometer or Fourier transform infrared spectrometer (FTIR). All
confirmations must be documented.
C. A confirmation must be performed to verify
the compound identification when positive results are detected on a sample from
a location that has not been previously tested. The confirmations must be
performed on organic tests, such as pesticides, herbicides, or acid-extractable
compounds, or when recommended by the analytical test method, except when the
analysis involves the use of a mass spectrometer or Fourier transform infrared
spectrometer. A confirmation is not required on positive results for samples
analyzed for diesel range organics and gasoline range organics under the
underground storage tank program. All confirmations must be
documented.
D. A laboratory must
document acceptance criteria for mass spectral tuning. The laboratory must
ensure that the tuning criteria meets the specifications in the approved method
or as established by the client, whichever is more stringent.
Subp. 10. Manual integrations.
If the integrations are not calculated by the equipment's software, a laboratory must document acceptable use of manual integrations and must have in place a system for review of manual integrations performed to verify adherence to the policies and procedures of the laboratory.
Subp. 11. Constant and consistent test conditions.
A. A
laboratory must ensure that the test instruments consistently operate within
the specifications required of the application for which the equipment is
used.
B. A laboratory must ensure
that glass and plastic containers are cleaned so that they meet the sensitivity
of the test method. Any cleaning and storage procedures that are not specified
by the test method must be documented in laboratory records and the laboratory
standard operating procedures manual.
Statutory Authority: MS s 144.97; 144.98
Disclaimer: These regulations may not be the most recent version. Minnesota may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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