What are the topical developments related to reference materials

Accreditation

An important trend is the accreditation of reference material producers. While ILAC-G12 was the leading document for an accreditation of this type in the past, it now follows the rules given by ISO Guide 34 (usually in combination with ISO/IEC 17025).

Networking

Although not a new idea, the networking of reference material producers has become prominent as a way of sharing the efforts of producing the high quality RMs needed to satisfy market demand and to avoid duplicate work. The ERM® programme in Europe is a recent example of such a network. Similar initiatives are under discussion in other parts of the world.

Metrological traceability

Establishing traceability and thus enabling comparability of measurement results is one of the major applications of RMs. But where does the traceability chain end? It may end at the respective RM or it may lead further up the metrological pyramid, linking the measurement results to a national standard, or, in an ideal case, even to the SI units. To enable the user to recognise the end of this chain, a clear statement about metrological traceability needs to be found on each RM certificate. This has rarely been done in the past; it must be a commitment for the present and the future.

Biological reference materials

There is a good choice and variety of reference materials offered for industrial applications or laboratory work with inorganic constituents. In the areas dealing with nutrition, health and life, however, only a limited number can be found in relation to the huge variety of tested samples (matrices, investigated properties, etc.), leaving RMs of this type to be among the most desired and urgently needed. As well as the identification of appropriate measurands, stability is a crucial factor here, and developing reliable biological RMs with an acceptable period of validity is one of the biggest future challenges for RM producers.

Speciation

The physical (e.g. hardness), chemical (e.g. reactivity) and biological (e.g. toxicity) behaviour of substances depend strongly upon their bonding status. Certification of individual species is a difficult task and thus only a few RMs are currently available. Considerable effort will have to be put into the development of speciation RMs to fill this gap.

For additional information see:

[1] ISO-Guide 34 (2000) General requirements for the competence of reference materials producers

[2] ISO/IEC 17025 (2005) General requirements for the competence of testing and calibration laboratories

[3] ILAC – G12 (2000) Guidelines for the requirements for the competence of reference materials producers(

http://www.ilac.org/documents/ILAC_G12-2000_guidelines_for_the_requirements_for
_the_competence_of_reference_materials_producers.pdf