Pennsylvania Code
Title 25 - ENVIRONMENTAL PROTECTION
Part I - Department of Environmental Protection
Subpart D - Environmental Health and Safety
Article VI - General Health and Safety
Chapter 252 - ENVIRONMENTAL LABORATORY ACCREDITATION
Subchapter D - QUALITY ASSURANCE AND QUALITY CONTROL REQUIREMENTS
Section 252.402 - Essential quality control requirements- chemistry

Universal Citation: 25 PA Code § 252.402

Current through Register Vol. 54, No. 44, November 2, 2024

(a) In addition to the requirements of § 252.401 (relating to basic requirements), laboratories performing testing or analysis of environmental samples in the area of chemistry shall comply with this section.

(b) When the method selected by an environmental laboratory in accordance with § 252.307 (relating to methodology) contains more stringent requirements than the requirements of this section, the environmental laboratory shall follow the more stringent requirements contained in the method.

(1) An environmental laboratory shall follow the initial calibration requirements of the method.

(2) The results of testing or analysis of environmental samples shall be determined from an initial calibration and may not be determined from any continuing calibration verification, unless otherwise required by regulation, method or program.

(3) The details of the initial calibration procedures including calculations, integrations, acceptance criteria and associated statistics shall be included or referenced in the laboratory's standard operating procedure.

(4) Raw data records shall be retained to permit reconstruction of the initial calibration, including identification or reference to the reagents, standards and supplies used, dates of analysis, instrument identification, results of the initial calibration, calibration criteria and analyst identification.

(5) Initial calibrations shall be verified with a standard obtained from a second manufacturer or with a standard from the same manufacturer if the verification standard is documented by the manufacturer as prepared independently of the standard used during initial calibration.

(6) The lowest standard used for initial calibration may not be below the detection limit. The lowest standard must be at or below the lower limit of the range of quantitation.

(d) Except for methods that explicitly allow initial calibration using a single concentration of standard, initial calibration shall be done using multiple concentrations of standards according to the requirements of this subsection.

(1) Unless otherwise specified in the method, the initial calibration must meet one of the following criteria:

(i) A relative standard deviation of less than 20% for the calculated response factors.

(ii) A coefficient of determination (r2) of 0.99 for a linear calibration curve.

(iii) A coefficient of determination (r2) of 0.999 for a nonlinear calibration curve determined with the use of at least 6 calibration standards or as otherwise specified by the Department.

(2) If the initial calibration fails to meet established acceptance criteria, corrective action shall be performed and all associated environmental samples shall be reanalyzed after an acceptable initial calibration is obtained. If reanalysis of the environmental samples is not possible, a new environmental sample shall be collected.

(3) If the results of testing or analysis of environmental samples that are below the initial calibration range are reported, the results shall be reported with appropriate data qualifiers.

(4) If the results of testing or analysis of environmental samples are above the initial calibration range, the environmental sample shall be diluted and reanalyzed or the results reported with appropriate data qualifiers. Sample results within the established calibration range will not require data qualifiers.

(5) The lowest calibration standard may not be below the detection limit and may not be above the MCL.

(6) If the method does not specify the number of calibration standards, the minimum number of calibration standards for a response factor or linear calibration, not including blanks or a zero standard, shall be determined as follows:

(i) For an initial calibration covering a range up to 20 times the lowest quantitation level, a minimum of three calibration standards shall be used.

(ii) For an initial calibration covering a range from greater than 20 times and up to 50 times the lowest quantitation level, a minimum of four calibration standards shall be used.

(iii) For an initial calibration covering a range greater than 50 times and up to 100 times the lowest quantitation level, a minimum of five calibration standards shall be used.

(e) For a method that explicitly allows calibration using a single concentration of a standard, not including a blank or zero concentration standard, the initial calibration shall meet the requirements of this subsection.

(1) Prior to the testing or analysis of environmental samples, the linear range of the instrument shall be established by analyzing a series of standards, one of which shall be at the lowest quantitation level.

(2) An initial calibration using a single calibration standard and a zero point shall be performed at the beginning of each analysis day.

(3) A standard corresponding to the lowest quantitation level must be analyzed with each analytical batch and must meet the acceptance criteria established by the method. When there are no established criteria in the method, an environmental laboratory shall determine internal criteria and document the procedure used to establish the acceptance limits.

(4) If the results of testing or analysis of environmental samples that are below the lowest quantitation level verification standard, specified in paragraph (3), are to be reported, the results shall be reported with appropriate data qualifiers.

(5) If the results of testing or analysis of environmental samples produce a result above the associated single point standard, the environmental laboratory shall do one of the following:

(i) Analyze a standard at or above the sample concentration that meets established acceptance criteria to validate linearity.

(ii) Dilute the sample so that the result falls below the single point calibration concentration.

(iii) Report the data with an appropriate data qualifier.

(f) Calibration verification requirements are as follows:

(1) A calibration verification standard shall be analyzed at the beginning and end of each analysis day. For methods that use an internal standard, a calibration verification standard is not required at the end of the analysis day unless specified in the method, or State or Federal law or regulation.

(2) A calibration verification standard shall be analyzed after every ten samples, unless a different frequency is specified in the method.

(3) At a minimum, the laboratory shall verify the calibration curve of each analytical batch with calibration verification standards at a low and a high level.

(i) The concentration of the low calibration verification standard shall be within the lower 20% of the calibration curve and not more than five times the lowest quantitation level.

(ii) The concentration of the high calibration verification standard shall be within the upper 20% of the calibration curve.

(4) Details of the calibration verification procedure including calculations, integrations, acceptance criteria and associated statistics shall be included or referenced in the laboratory's standard operating procedure.

(5) Raw data records shall be retained to permit reconstruction of the calibration verification.

(6) Acceptance criteria for calibration verification standards in the method shall be followed. When there are no established criteria in the method, an environmental laboratory shall use the acceptance criteria described in an equivalent method for the same type of analysis. When an equivalent method is not available, the laboratory shall establish control charts in accordance with Standard Methods for the Examination of Water and Wastewater (available from the American Public Health Association, 800 I Street, NW, Washington, D.C. 20001) to determine internal criteria and document the procedure used to establish the acceptance limits.

(7) If a calibration verification standard fails the established acceptance criteria, an environmental laboratory shall initiate corrective actions. If the corrective actions fail to produce an immediate consecutive calibration verification standard within the acceptance criteria, a new calibration verification standard shall be prepared. If the freshly prepared calibration verification standard fails to produce a result within the established acceptance criteria, the environmental laboratory shall recalibrate the test or analysis according to the method or as set forth in subsection (c) and as set forth in either subsection (d) or (e).

(8) To the extent possible, and as provided by paragraph (1), environmental samples not bracketed by acceptable calibration verification standards shall be reanalyzed. If the calibration verification standard is found to be out of control, and the results of the testing or analysis of environmental samples are to be reported, all environmental samples associated with the failed calibration verification standard shall be documented and the results flagged in an unambiguous manner on the sample analysis report with the appropriate data qualifiers.

(g) Method blank requirements are as follows:

(1) A method blank must be processed along with and under the same conditions as the associated environmental samples including all steps of the analytical procedure.

(2) A method blank must be analyzed at a minimum of one per preparation batch. When no separate preparation method is used (example: volatiles in water), the batch shall be defined as no more than 20 environmental samples that are analyzed together using the same method, personnel and lots of reagents.

(3) A method blank must consist of a matrix that is similar to the associated environmental samples and is free of the analytes of interest. When a matrix that is similar to the associated environmental samples that is free of the analytes of interest is not available, reagent water or an artificial or simulated matrix may be used.

(4) A method blank is considered contaminated if one of the following applies:

(i) The concentration of a target analyte in the method blank is at or above the reporting limit established by the method, by the laboratory or by regulation.

(ii) The contamination in the method blank otherwise affects the environmental sample results as described in the method or in individual project data quality objectives.

(5) If a contaminant is detected in the method blank, the source of contamination shall be investigated and measures shall be taken to minimize or eliminate the problem.

(6) Raw data records shall be retained to permit reconstruction of the method blank.

(7) To the extent possible, any environmental samples associated with a contaminated method blank shall be reprocessed for analysis. If a contaminated method blank is found to be out of control, and the results of the testing or analysis of environmental samples are to be reported, all environmental samples associated with the contaminated method blank shall be documented and the results flagged in an unambiguous manner on the sample analysis report with the appropriate data qualifiers.

(h) Laboratory control sample requirements are as follows:

(1) A laboratory control sample must be processed along with and under the same conditions as the associated environmental samples, including all steps of the preparation and analytical procedure.

(2) A laboratory control sample must consist of a matrix that is similar to the associated environmental samples and is free of the analytes of interest. When a matrix that is similar to the associated environmental samples that is free of the analytes of interest is not available, reagent water or an artificial or simulated matrix may be used.

(3) An environmental laboratory shall analyze a laboratory control sample at a minimum of one per preparation batch. When no separate preparation method is used, for example volatiles in water, the batch shall be defined as no more than 20 environmental samples that are analyzed together with the same method, personnel and lots of reagents.

(4) All analyte concentrations in the laboratory control sample must be within the calibration range of the method and at or below the maximum contaminant level.

(5) The components to be spiked into the laboratory control sample must be as specified by the method or other regulatory requirement. In the absence of specified components, the environmental laboratory shall use the following:

(i) For those components that interfere with an accurate assessment, such as spiking simultaneously with technical chlordane, toxaphene and PCBs, the laboratory control sample must represent the chemistries and elution patterns of the components to be reported.

(ii) For methods with more than ten analytes, a representative number may be chosen. The analytes selected shall be representative of all chemistries and analytes reported and shall be chosen using the following criteria:

(A) Targeted components shall be included in the laboratory control sample over a 2-year period.

(B) For methods that include one to ten components, the laboratory control sample must contain all components.

(C) For methods that include 11-20 components, the laboratory control sample must contain at least 10 components or 80%, whichever is greater.

(D) For methods with more than 20 components, the laboratory control samples must contain at least 16 components.

(6) Each individual laboratory control sample shall be compared to the acceptance criteria in the method. When there are no established criteria in the method, an environmental laboratory shall use the acceptance criteria described in an equivalent method for the same type of analysis. When an equivalent method is not available, the laboratory shall establish control charts in accordance with Standard Methods for the Examination of Water and Wastewater (available from the American Public Health Association, 800 I Street, NW, Washington, D.C. 20001) to determine internal criteria and document the procedure used to establish the limits.

(7) Raw data records shall be retained to permit reconstruction of the laboratory control sample.

(8) Environmental samples associated with an out of control laboratory control sample shall be reprocessed and reanalyzed from the beginning of the method or the results reported with the appropriate data qualifiers.

(i) Sample duplicate requirements are as follows:

(1) A sample duplicate or matrix spike duplicate must be processed along with and under the same conditions as the associated environmental samples, including all steps of the preparation and analytical procedure.

(2) A sample duplicate or matrix spike duplicate shall be analyzed at a minimum of one per preparation batch. When no separate preparation method is used, for example volatiles in water, the batch shall be defined as no more than 20 environmental samples that are analyzed together using the same method, personnel and lots of reagents.

(3) An environmental laboratory shall document the calculations used for determining the relative percent difference or other statistical method for evaluation of the duplicate pairs.

(4) Each duplicate relative percent difference shall be compared to the acceptance criteria in the method. When there are no established criteria in the method, an environmental laboratory shall use the acceptance criteria described in an equivalent method for the same type of analysis. When an equivalent method is not available, the laboratory shall establish control charts in accordance with Standard Methods for the Examination of Water and Wastewater (available from the American Public Health Association, 800 I Street, NW, Washington, D.C. 20001) to determine internal criteria and document the procedure used to establish the acceptance limits.

(5) For duplicate results outside established criteria, corrective action shall be documented and the data reported with appropriate data qualifiers.

(j) Surrogate spike requirements are as follows:

(1) Surrogate compounds, when commercially available, shall be added to all samples, standards and blanks for all organic chromatography test methods.

(2) Surrogate compounds shall be chosen to represent the various chemistries of the target analytes in the method.

(3) The results of the surrogate spike shall be compared to the acceptance criteria published in the method. When there are no established acceptance criteria for surrogate recovery in the method, the environmental laboratory shall use the acceptance criteria described in an equivalent method for the same type of analysis. When an equivalent method is not available, the laboratory shall establish control charts in accordance with Standard Methods for the Examination of Water and Wastewater (available from the American Public Health Association, 800 I Street, NW, Washington, D.C. 20001) to establish internal criteria and document the method used to establish the acceptance limits.

(4) For surrogate spike results outside established criteria, corrective action shall be documented and the data reported with appropriate data qualifiers.

(k) Detection limit requirements are as follows:

(1) A detection limit shall be determined by the protocol in the method or regulation. If the protocol for determining detection limits is not specified in the method or regulation, the environmental laboratory shall select a procedure that reflects instrument limitations and the intended application of the method.

(2) A detection limit study is not required for any component for which spiking solutions or quality control samples are not available, such as temperature. A detection limit study is not required for testing or analysis where the results are logarithmic, such as pH, or when the results are expressed as presence or absence.

(3) A detection limit shall be initially determined for the compounds of interest in each method in a matrix in which neither the target analyte nor interferences are at a concentration that would impact the results. The detection limit shall be determined in the matrix of interest.

(4) A detection limit shall be determined each time there is a change in the method that affects how the test is performed or that affects the sensitivity of the analysis.

(5) The sample processing steps of the method shall be included in the determination of the detection limit.

(6) Supporting data shall be retained to permit reconstruction of the detection limit study.

(7) An environmental laboratory shall have an established procedure to relate detection limits with quantitation limits.

(8) The method's lower limit of quantitation shall be established and shall be above the detection limit.

(l) When retention times are used for the identification of an analyte, an environmental laboratory shall develop and document acceptance criteria for retention time windows. The laboratory shall document acceptance criteria for mass spectral tuning.

(m) When manual integrations are performed for chromatography methods, the laboratory shall have written procedures for manual integrations and instrument manipulations.

(1) The manual integration procedures must detail the steps taken to perform the integrations and define proper and improper integrations.

(2) The laboratory shall document manual integrations with the reason for the integration and the initials of the individual performing the integration.

(3) The laboratory shall retain a copy of the data before and after manual integration.

(n) The laboratory shall employ confirmation techniques to verify the compound identification when positive results are detected on a sample from a location that has not been previously tested by the laboratory or for a sample location that has not previously yielded detectable results for a particular compound.

(1) The confirmations shall be performed when analysis involves the use of an organic chromatography method not utilizing a mass spectrometer.

(2) The confirmations shall be documented.

(o) Records of all equipment, reference materials, reagents, and supplies shall be maintained in accordance with § 252.306 (relating to equipment, supplies and reference materials).

The provisions of this §252.402 amended under 27 Pa.C.S. §§ 4103(a), 4104 and 4105; and section 1920-A of The Administrative Code of 1929 (71 P.S. § 510-20).

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