Certified reference material

Certified Reference Material

Certified Reference Materials (CRMs) are essential tools in the field of analytical chemistry and laboratory science. They are used to ensure the accuracy and traceability of measurements in various scientific disciplines. CRMs are materials or substances with a precisely known composition or property value, certified by a technically valid procedure, and accompanied by a certificate that provides the value of the specified property, its associated uncertainty, and a statement of metrological traceability.

Definition and Purpose

CRMs are used to calibrate measurement systems, validate analytical methods, and assess the performance of laboratories. They play a crucial role in quality assurance and quality control processes. The certification of these materials is carried out by competent bodies, ensuring that the reference values are reliable and traceable to international standards.

Types of Certified Reference Materials

CRMs can be classified based on their physical state, intended use, or the property they are certified for. Common types include:

• Gas Mixtures: Used in environmental monitoring and industrial applications.
• Solutions: Often used in chemical analysis for calibration of instruments like spectrometers.
• Solid Materials: Used in metallurgy, geology, and material science.
• Biological Materials: Used in clinical laboratories and biotechnology.

Certification Process

The certification of a reference material involves several steps:

1. Selection of Material: The material must be homogeneous and stable over time. 2. Characterization: The material is analyzed using multiple methods to determine its properties. 3. Homogeneity Testing: Ensures that the material is uniform throughout. 4. Stability Testing: Assesses how the material's properties change over time. 5. Assignment of Property Values: The certified values are determined and documented. 6. Documentation and Certification: A certificate is issued, detailing the certified values, uncertainty, and traceability.

Importance in Analytical Chemistry

CRMs are vital for:

• Method Validation: Ensuring that analytical methods produce accurate and reliable results.
• Instrument Calibration: Providing a benchmark for instrument performance.
• Quality Control: Monitoring and maintaining the quality of analytical results.
• Regulatory Compliance: Meeting the requirements of regulatory bodies and standards organizations.

Challenges and Considerations

While CRMs are invaluable, there are challenges associated with their use:

• Cost: High-quality CRMs can be expensive.
• Availability: Not all materials are available as CRMs.
• Storage and Handling: Proper storage conditions are necessary to maintain their integrity.

Also see

• Analytical Chemistry
• Quality Control
• Metrology
• Calibration
• Traceability