Analytical Standards - Terminology

Terminology

        • CRM - Certified Reference Materials provide the highest level of accuracy, uncertainty, and traceability.

        • RM - Reference Materials are a step down from CRM and should be supplied by an accredited producer.

        • ISO 17034 – provide general requirements for the competence of reference material producers.  These cover the production of all reference materials, including CRMs.

        • ISO 17025 – provide international standards for testing and calibration laboratories, enabling laboratories to demonstrate that they operate competently and generate valid results,                  thereby promoting confidence in their work.

        • ISO 17043 - specifies general requirements for the competence of providers of proficiency testing materials and for the operation of proficiency testing schemes.

        • ISO 9001 - sets out the criteria for a quality management system.

        • NIST Traceable - National Institute of Standards and Technology (NIST) traceable calibration certifies that the lab or manufacturer in question is equipped and able to calibrate                          equipment to NIST standards and that products by that manufacturer match NIST-maintained measurement standards.

Qualitative Standards:

        • Typically used for the determination of the absence or presence of an analyte.
        • Can be ISO accredited, meaning it was made to ISO standards.
        • Typically, these are RM materials.
        • Will have the concentration reported though high precision is not required.
        • The purity of the raw material does not need to exceed 90%.
        • The QC testing often involved just one testing method.
        • These are typically less expensive than quantitative products.
 

Quantitative Standards:
        • Typically used to determine the amount of an analyte.
        • Typically, these are CRMs, but they can be a RM.
        • Can be used as a qualitative standard.
        • Should be ISO 17034 accredited; not all providers meet this requirement.
        • Will have the concentration reported, typically to 4 significant figures.
        • Will have the raw material lot reported, and purity stated.
        • The concentration will be corrected for the purity of the raw material.
        • Will have the % uncertainty stated.
        • Will be NIST or similarly traceable.
        • The QC testing will typically include multiple testing methods.