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Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement (v.8, #10)
A national traceability system for chemical measurements by Wolfgang Richter; Bernd Güttler (pp. 448-453).
Current developments in Germany for establishing a traceability system for chemical measurements are reported. The focus is on a dissemination mechanism which employs chemical calibration laboratories accredited within the framework of the German Calibration Service (DKD) and acting as "multipliers" between the national standards level and the user level by providing the user with calibration means which are traceable to the SI via national standards. At the national standards level, a network of high-level chemistry institutes coordinated by the national metrology institute, PTB, provides the primary references for chemical measurements.The use of the metrological dissemination system provided by the DKD also for chemical measurements is a logical extension of a traceability mechanism, successful for more than two decades in general metrology, to metrology in chemistry. In detail, traceability structures in clinical chemistry, electrochemistry, elemental analysis and gas analysis are described. This system has become an important part of the efforts made in Germany to support chemical laboratories in meeting the traceability requirements of the market and of legal regulations.
Keywords: National traceability system; Chemical calibration laboratories; Clinical chemistry; Electrochemistry; Elemental analysis; Gas analysis
Testing for foods derived from modern biotechnology: opportunities and limitations for metrology by Markus Lipp (pp. 454-460).
Various countries have established labeling schemes for food derived from modern biotechnology. As a consequence, test methods need to be available to industry and regulators. The three test options, bioassays, protein-based and DNA-based test methods, are discussed. None of these methods is able to directly measure the percentage of foods derived from modern biotechnology by weight (weight-%), the unit in which most of the thresholds for food labeling in the different countries (if any) have been established. The conversion of the measurement units to weight-% is difficult to achieve and influenced by a number of biological factors. Metrology can aid the standardization of methods enormously by defining clearly the relationships between measurement units and other units of interest (e.g. legal thresholds).
Keywords: biotechnology; Genetically modified organisms; Polymerase chain reaction; Reference materials
Practical ways in establishing traceability in chemical and other measurements in Mexico by Yoshito Mitani; Alejandro Perez-Castorena (pp. 461-466).
Practical ways to establish traceability in chemical measurements are examined to understand such diversified field measurements, which cover all principles of chemical and other measurements, and are considered to be applicable to measurements of materials properties in general. A description is given of several initiatives in Mexico to establish a comparable measurement and calibration capability and dissemination scheme. Additional efforts for establishing traceability in field measurements are described in order to achieve traceable measurements harmonized with other countries, with particular emphasis on the accreditation of analytical laboratories based on their technical competence.
Benefits of the implementation of a metrological structure for water analyses by Ph. Charlet; A. Marschal (pp. 467-474).
Traceability of measurements still often remains a non-operational notion for end-user chemists. A practical project, sponsored by the French Ministry of Research, has been conducted to evaluate and to demonstrate possible benefits of the implementation of a metrological structure for improvement of the quality of water analyses. LNE (Laboratoire National d'Essais) was in charge of the build up of the traceability chain in a concrete case of determination of some heavy metals (cadmium and lead) in a groundwater. Pure solutions for calibration and a matrix RM have been certified by LNE and then used by 46 labs (mainly French) in a inter-laboratory study. Results have shown a measurable bias in lead analysis in the groundwater for all methods in routine use by laboratories. This project has demonstrated the interest of a metrological approach for method calibration, method validation and estimation of measurement uncertainty.
Keywords: Metrology; Traceability; Analytical chemistry; Certified reference material; Water analyses
Traceability to units by Gary Price (pp. 475-476).
On the grounds that clear and direct communication is required of us today, it is proposed that traceability be regarded as the ability to demonstrate that measurements are what they are purported to be and that traceability is thus to measurement units rather than reference values per se. It is suggested that such an approach may give greater flexibility in the establishment, maintenance and propagation of traceability, and that accreditation practices are becoming central to the practical establishment of traceability for chemical and biological measurement.
Keywords: Traceability; Units; Reference value; Metrology; Accreditation; Scale
Reply to "Measurement uncertainty and doping control in sport" by A. van der Veen, Accred Qual Assur (2003) 8:334–339
by Peter Van Eenoo; Frans T. Delbeke (pp. 477-479).
UK delivery of traceable chemical measurements in the 21st century: building on the foundation of the VAM programme by Mike Sargent (pp. 480-482).
The paper discusses the requirements for achieving traceable chemical measurements in the UK. It is emphasised that success will depend on establishing an appropriate UK chemical measurement infrastructure and encouraging reference and field laboratories to make use of it. The demanding requirements of the BIPM Mutual Recognition Arrangement (MRA) also require a point of focus to link UK reference laboratories into international metrology. Two key factors are described which have provided the UK with the means to meet these requirements and which have established a sound basis on which to build a system of traceable chemical measurements in the 21st century. These two factors are LGC's long-standing role as the UK's national centre for analytical chemistry and the development and delivery over many years of the UK's Valid Analytical Measurement (VAM) Programme.
Keywords: Traceability; Laboratory of the Government Chemist; Valid Analytical Measurement; Calibration
Disseminating traceability in chemical measurement: Principles of a new EURACHEM/CITAC guide
by S. L. R. Ellison; A. Williams (pp. 483-485).
David Burnett: A practical guide to accreditation in laboratory medicine.
by James O. Westgard (pp. 486-486).