Certified reference materials
Encyclopedia
Certified Reference Materials (CRMs) are ‘controls’ or standards used to check the quality and traceability of products. A reference standard for a unit of measurement
Measurement
Measurement is the process or the result of determining the ratio of a physical quantity, such as a length, time, temperature etc., to a unit of measurement, such as the metre, second or degree Celsius...

 is an artifact that embodies the quantity of interest in a way that ties its value to the reference base for calibration
Calibration
Calibration is a comparison between measurements – one of known magnitude or correctness made or set with one device and another measurement made in as similar a way as possible with a second device....

.

At the highest level, a primary reference standard is assigned a value by direct comparison with the Standard (metrology)
Standard (metrology)
In the science of measurement, a standard is an object, system, or experiment that bears a defined relationship to a unit of measurement of a physical quantity. Standards are the fundamental reference for a system of weights and measures, against which all other measuring devices are compared...

. For example, mass is defined by an artifact maintained by the Bureau International des Poids et Mesures in Sèvres, France. A primary standard is usually under jurisdiction of a national standards body.

Since most analytical instrumentation is comparative, it requires a sample of known composition (reference material) for accurate calibration. These reference materials as produced under stringent manufacturing procedures and differ from laboratory reagents in their certification and the traceability of the data provided.

Quality management system
Quality management system
A quality management system can be expressed as the organizational structure, procedures, processes and resources needed to implement quality management.-Elements of a Quality Management System:# Organizational structure# Responsibilities# Methods...

s involving laboratory accreditation under national and international accreditation/certification standard
International standard
International standards are standards developed by international standards organizations. International standards are available for consideration and use, worldwide...

s such as ISO 9000
ISO 9000
The ISO 9000 family of standards relates to quality management systems and is designed to help organizations ensure they meet the needs of customers and other stakeholders . The standards are published by ISO, the International Organization for Standardization, and available through National...

 and ISO 17025 require the use of Reference Materials.

Whilst Certified Reference Materials are preferred, their availability is limited. The available Reference Materials generally differ only in the detail provided on the certificate.

Definitions as ISO Guide 30 (1992 edition).

Reference Material (RM)

A material or substance one or more of whose property values are sufficiently homogeneous 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 Reference Material, accompanied by a certificate, one or more of whose property values are certified by a procedure which establishes its traceability to an accurate realisation of the unit in which the property values are expressed and for which each certified value is accompanied by an uncertainty at a stated level of confidence.

Production

Production of CRMs is split into two categories: Calibrants and matrix CRMs. Calibrants are pure standards used for calibrating instruments. These are usually produced by commercial producers (Merck KGaA, Sigma Aldrich, Biopure, Chem-Lab, NSI Solutions and SPEX CertiPrep) and companies that specialize in CRMs.
Matrix CRMs contain an analyte in a sample (e.g. lead in fish). Due to the difficulty in its production and value assignment, these are usually produced by national or transnational metrology institutes like NIST (USA), BAM
Bundesanstalt für Materialforschung und -prüfung
The Federal Institute for Materials Research and Testing or Bundesanstalt für Materialforschung und -prüfung is a German material research institute.-History:...

 (Germany), KRISS
Kriss
Kriss might refer to:People*Eric Kriss, a musician, writer and business executive*Grigory Kriss, a Soviet Russian world champion épée fencer*Kristina Kiss, a Canadian football midfielderInstitute* Miscellaneous...

 (Korea) and IRMM(European Commission).

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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