TECHNICAL HELP: GLOSSARY OF TERMS

The preparation of Certified Reference Materials (CRMs) requires a complete understanding of the technical, regulatory, and quality processes used to manufacture, store, test and certify the reference materials. Here are a few of the key terms Pharmaceutical Resource Associates use as outlined in ISO Guide 30, 1992.

Reference Material (RM) – Material or substance one or more of whose property values are sufficiently homogenous and well established to be used for the calibration of an apparatus, the assessment of a measurement method, or for assigning values to materials.

Certified Reference Material (CRM) – A Certified Reference Material meets all the criteria of a Reference Material and accompanied by a certificate. One or more of the property values assigned on the certificate are certified by a procedure which establishes its traceability to an accurate realization of the unit in which the property is expressed, AND for which each certified value is accompanied by an uncertainty at a stated confidence level.

Primary Standard – Standard that is designated or widely acknowledged as having the highest metrological qualities and whose value is accepted without reference to other standards of the same quality, within a specified context.

Secondary Standard – Standard whose value is assigned by comparison with a primary standard of the same quantity; most CRMs are secondary standards as the certification of their property values is carried out by a procedure traceable to primary standards.

Stability – Ability of a Reference Material, when stored under specified conditions, to maintain a stated property value within specified limits for a specified period of time.

Certified Value – Value that appears in the certificate accompanying the material.

Uncertified Value – Value or quantity, included in the certificate of a CRM, which is provided for information only but is not certified by the producer or certifying body.

Uncertainty of Certified Value – Estimate attached to a certified value of a quantity that characterizes the range of values within which the “true value” is asserted to lie with a stated level of confidence.

Traceability – Property of the result of a measurement or the value of a standard whereby it can be related, with a stated uncertainty, to stated references, usually national or international standards, through an unbroken chain of comparisons.

Certification of a Reference Material – Procedure that establishes the values of one or more properties of a material or substance by a process ensuring traceability to an accurate realization of the units in which the property values are expressed, and that leads to the issuance of a certificate.

Certified Reference Material Producer – Technically competent body (organization or firm, public or private) that produces certified reference materials in accordance with the general and statistical principals detailed in ISO Guides 31 and 35. Pharmaceutical Resource Associates is the leading Certified Reference Material Producer for the pharmaceutical industry.