The objective of the programme is twofold: to promote the development of a structured measurement technology system for chemistry, nationally as well as internationally, and to increase the understanding and knowledge of quality assurance of chemical measurements. The specific aims of the activity is to build a profound knowledge-base within the area, to actively participate in European and international quality assurance efforts, and to provide SP with a leading role in the Swedish measurement technology infrastructure within the field of chemistry. Experimental activities are being conducted in e.g. primary measurements of isotope dilution, x-ray fluorescence, and conductivity. An EU-financed project on the analysis of biofuels is also ongoing.
International aspects of measuring quality and quality assurance
The results of chemical measurements provide the basis for important decisions concerning the environment, health and security. When monitoring the import and export of goods and foodstuffs, it is essential that the monitoring bodies are able to trust any certificates and analysis documents accompanying the goods. Globalised trade increases the demands on chemists to be able to prove the reliability of measuring results, i. e. to demonstrate the measurement quality. An increase in multidisciplinary research has provided chemists with new inspiration, e. g. from physicists, on ways of extending their traditional quality assurance methods. This includes attempts to create more transparent hierarchic structures for chemical measurements, so-called traceability chains, as well as other ways of evaluating the measurement uncertainty. The objective of quality assurance activities is to facilitate the evaluation of whether or not measurements differ, and if so, how much (comparability). New international guidelines for how to evaluate and present such uncertainty is now being incorporated into the policy documents and quality standards of various authorities.
The aim of the programme is to follow and report on the international development regarding measurement quality, to help develop traceable chemical measuring methods, as well as, through information, education and advice, support chemical laboratories in their quality assurance efforts.
SP is active within several organisations monitoring the international development:
- CCOM (Consultative Committee for Amount of Substance), the advisory committee for chemistry within the International Bureau of Weights and Measures. This body coordinates international metrology activities.
- EURACHEM is a European forum for analytical chemistry. Several new documents concerning quality assurance may be found on their website. More than 600 copies of SP’s translation into Swedish of the EURACHEM/CITAC guide on measurement uncertainty (“Quantifying Uncertainty in Analytical Measurement”) have been distributed to date. It has since been reprinted (SP Report 2001-24) and may also be found on the Swedish-language EURACHEM/EUROLAB website. Within the framework of EURACHEM, SP has hosted one workshop on comparative testing (Quality Assurance 2001, 6 (4-5)) and two workshops on measurement quality (in 2004, www.chemsoc.se).
- EUROLAB is EURACHEM’s counterpart in the area of testing.
- EUROMET is the regional European metrology organisation. Among other things, their committee for metrology in chemistry initiates testing comparisons between expert laboratories. SP is also active in IUPAC (The International Union of Pure and Applied Chemistry), in CITAC, an international co-operative body focusing on traceability and measurement uncertainty in analytical chemistry, as well as in CCQM, the advisory committee for chemistry within the International Bureau of Weights and Measures.
We can provide advice and guidelines on different aspects of reference materials through our contacts with ISO REMCO, as well as through our participation in workgroups with participants from EURACHEM, EUROLAB and European accreditation bodies. Also, SP is the Swedish contact for two international databases on reference material: COMAR and VIRM.
In the area of comparative testing, SP cooperates with IRMM and EPTIS.
The Institute for Reference Material and Measurements (IRMM) is a part of the European Commission Joint Research Centre (EC-JRC). SP provides information, coordinates Swedish participation, and conducts projects within the IRMM International Measurement Evaluation Programme (IMEP). In these comparative tests, certified test samples with independent and traceable reference values are used. By compiling the participant’s results, a good picture of the measurement quality in important areas may be obtained. The certification is then issued based on the applied measuring principle, e.g. isotope dilution mass spectrometry (IDMS).
The EPTIS database is an open web resource where analysis laboratories may find comparative testing results. SP is its Swedish contact.
Examples of ongoing projects 2006-2008:
- “Measurement uncertainty in sampling”. The total uncertainty of an analysis is derived both from the sampling process as well as from the measuring itself. Today, there are adequate guidelines for the estimation of uncertainty in the measuring process, but not for the sampling. In collaboration with EURACHEM, Nordtest and LKAB, SP participates in a three-year project aiming at producing guidelines for the estimation of sampling uncertainty.
- “Various methods for calculating measurement uncertainty”. There are several ways of calculating uncertainty, which may provide totally different results. SP participates in a three-year project together with EUROLAB/EURACHEM aimed at providing guidelines for how to calculate the uncertainty.