The Centre d’expertise en analyse environnementale du Québec (CEAEQ) holds ISO/IEC 17043:2023 accreditation (French) (“Conformity assessment — General requirements for the competence of proficiency testing providers”) as well as ISO 17034:2016 accreditation (“General requirements for the competence of reference material producers”). All reference materials produced by the CEAEQ meet the requirements set out in these standards, particularly with respect to homogeneity, stability and quality assurance. The CEAEQ’s scopes of accreditation can be consulted on the website of the Conseil canadien des normes.
All analyses required for the validation of reference materials used in chemical analyses are carried out in the CEAEQ’s laboratories, which hold ISO/IEC 17025:2017 accreditation (“General requirements for the competence of testing and calibration laboratories”) from the Conseil canadien des normes.
Frequent or regular use of reference materials helps ensure the quality and reliability of environmental analysis methods. In a laboratory, reference materials are integrated into analytical sequences and allow verification of the effectiveness of the analytical process, from sample pretreatment through to assay.
The reference materials prepared at the CEAEQ are stable and homogeneous. The matrices used are as representative as possible of the environments and concentration levels prescribed by the environmental regulations in force in Québec. Thanks to these characteristics, the reference materials manufactured at the CEAEQ are essential tools for maintaining the credibility of a quality assurance and quality control program.
Among other things, the CEAEQ produces reference materials for chemical analyses in natural or artificial matrices. These matrices include drinking water, groundwater, municipal and industrial wastewater, industrial waste, wastewater treatment plant sludge, contaminated soil and hazardous materials, including waste oil and trapped industrial gaseous effluents. The materials are produced for several inorganic and organic parameters or groupings of parameters.
Water |
Drinking water |
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Wastewater |
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| Soils | Inorganic or organic soil that may originate from contaminated land, to which the parameters required for analysis have been added |
Wastewater treatment plant sludge |
Dried and ground sludge to which the parameters required for analysis have been added |
Hazardous materials |
Liquid waste, solid waste or oil to which the parameters required for analysis have been added in solvents such as water or dichloromethane |
Industrial gaseous effluents |
Acetone or 3% volume-for-volume (V/V) hydrogen peroxide, or filters to which the parameters required for analysis have been added in the appropriate solvent |
Vegetation |
Ground forage to which the required parameters, in dry form, have been added for analysis |
The reference material validation process currently used at the CEAEQ is unique in Canada. In addition to having two laboratories accredited to the ISO/IEC 17025 standard, which use reference materials for in-house quality control monitoring, the Centre uses several reference materials to evaluate the performance of accredited laboratories under the Programme d’accréditation des laboratoires d’analyse of the Ministère.
The use of statistical data obtained during proficiency testing and validation analyses ensures greater reliability of the reference materials.
The expected values of reference materials are generally determined by using values measured by the CEAEQ’s laboratories. The expected value is calculated in accordance with the ISO/IEC 13528 standard.
The acceptability and warning limits are calculated from the relative variation criteria (CVR). The CVR values are, in turn, determined from the statistical data from the proficiency testing of the Programme d’accréditation des laboratoires d’analyse. In addition, for certain parameters, the CVR are determined according to the specific conditions and requirements related to the analytical methods. They are estimated for each evaluated parameter and are revised. The CVR are modified as needed based on the results obtained during proficiency testing. The complete list of CVR is found in the document “Relative Variation Criteria” (DR‑12‑CVR, French).
To determine a limit, in the case of a series of analytical results, we use the following formulas:
Warning limit = Expected value * 2CVR
Control limit = Expected value * 3CVR
