GMP News No. 128
21 August 2001
The term of 'measurement uncertainty' is reinforced in the new norm ISO 17,025 on the accreditation of analytical control and calibration laboratories, which takes the place of the former EN 45001.
Even though this new ISO norm is less relevant for the pharmaceutical industry and in addition the term of 'measurement uncertainty' is being used within the pharmaceutical industry mainly in the field of calibration, it is certainly interesting to find specific literature on this topic - above all if it can be accessed directly on the Internet.
There is, for example, the nine-page publication 'The Expression of Uncertainty in Quantitative Testing' of the European Cooperation for Accreditation of Laboratories (DAR-EM25, formerly EAL-G23, 1998) or the eight-page publication 'Uncertainty of test results (Result Uncertainty)' (DAR-EM22). Both can be found on the website of the German Accreditation Council (DAR) at http://www.dar.bam.de/indexe.html/, which is available in German and in English.
Detailed information can also be found in the EURACHEM/CITAC Guide 'Quantifying Uncertainty in Analytical Measurements' at http://www.eurachem.ul.pt/. This 120-page guide serves as interpretation of the 'ISO Guide to the Expression of Uncertainty in Measurements.' By the way, from the same website you can download the comprehensive EURACHEM Guide with the title 'The Fitness for Purpose of Analytical Methods, a Laboratory Guide to Method Validation and Related Topics,' which is very informative!
Measurement uncertainty is very important in the pharmaceutical laboratory also in connection with reference substances. At the international conference 'Reference Standards' of the European Compliance Academy, which takes place from 29-30 November 2001 in Berlin, a separate lecture is dedicated to this topic, and certainly the consequences of measurement uncertainty for the reference substances of the pharmacopoeias (Ph.Eur. and USP) will be discussed.