Vol. 23, No. 1
of Chemical Measurements
International Evaluation Program Reveals True Situation
D. P. Taylor, Ioannis Papadakis, Lutgart Van Nevel, Ciaran Nicholl,
and Prof. Paul De Bièvre*
The BIPM Gets Involved
Measurement Evaluation Program (IMEP)
A Practical Example:
IMEP-9 Trace Elements in Water
The Way Forward
The wide variation in chemical trace measurements was first brought
to my attention by Prof. De Bièvre at the 1998 meeting of the
Committee on Chemistry and Industry (COCI) in Johannesburg, South Africa.
During our 1999 meeting in Berlin, Germany, he again presented data
demonstrating a huge (±50%) variation in trace element (Pb, Cd, Fe,
and Zn) concentrations in water even from "accredited" laboratories.
Similar problems were demonstrated for analysis of catalyst metals (Pt)
in car exhaust material. Because such data are increasingly used in
decision-making areas of industrial concern, our committee adopted "Reliability
of Chemical Measurements" as a new, formal project, with Prof.
De Bièvre as coordinator. Interest was immediately demonstrated
by UNESCO (Dr. A. Pokrovsky), and cooperative information dissemination
efforts began. Although a brief summary of the concerns, "Metrology
in Chemistry", had been published in Chemistry and Engineering
News (C&EN, 31 May 1999, p. 29), COCI encouraged Prof. De Bièvre
to submit a more detailed summary to Chemistry International (CI). This
article provides "snapshot" pictures of chemical measurement
(un)reliability, with many practical, societal implications.
Dr. A. Nelson Wright
Chairman, IUPAC Committee on Chemistry and Industry (COCI)
Chemical measurements form the basis of many important economic, political,
environmental, medical, and legal decisions. Each day, millions of such
measurements are carried out throughout the world. The real basis for
decision-making and implementing regulations depends on the comparability
and reliability of the results of these chemical measurements. The European
Commission requires that measurements performed in one Member State
must be acceptable to all other Member States in the Union. This process
requires that such reliability be demonstrated. Moreover, the results
of European chemical measurements must also be transparent and clearly
understood by Europes trading partners in the whole world and
vice versa. Globalization of commerce and the need for fair trade require
knowledge of the degree of equivalence of the measurement results as
they affect the value of traded goods.
Committee on Chemistry and Industry (COCI) has submitted the above article,
prepared by Dr. Philip D. P. Taylor (Joint Research Centre-European
Commission, Institute for Reference Materials and Measurements, Retiesweg,
B-2440 Geel, Belgium; E-mail: [email protected]),
Dr. Ioannis Papadakis ([email protected]),
Mrs. Lutgart Van Nevel ([email protected]),
Dr. Ciaran Nicholl ([email protected]),
and Prof. Paul De Bièvre (Duineneind 9, B-2460 Kasterlee, Belgium;
E-mail: [email protected]).
COCI Chairman Dr. A. Nelson Wright (12539 Ranger, Montreal, Quebec H4J
2L7, Canada; E-mail: [email protected])
contributed the Introduction.