Reinhard Zeleny and Heinz Schimmel (JRC-IRMM) have received the CITAC Best Paper Award 2012 for their publication "Influence of the approach to calibration on the accuracy and the traceability of certified values in certified reference materials" [R. Zeleny, H. Schimmel (2012) Trends Anal. Chem. 33, 107-116,].
CITAC grants this award to three selected papers every year. Reinhard Zeleny attended the 28th CITAC members' meeting on 14 April in Paris to receive the award and to give a presentation about the paper.
JRC-IRMM's paper compares two calibration approaches in laboratory intercomparisons for assigning values to candidate certified reference materials (CRMs), based on data obtained in recent certification projects in the veterinary drug-residue field, i.e. chloramphenicol in pork (ERM-BB130) and oxytetracycline in milk (ERM-BB492).
First, all laboratories used the same calibrant (common calibrant, a commercially available substance, extensively characterized for purity and identity), and second, each laboratory used its in-house calibrant (commercially available substance, purity as indicated by the provider). Each measurement series included two calibration curves, one with the common calibrant, and one with the in-house calibrant. The obtained data pointed at an overestimation of the purity of the in-house calibrants and revealed decreased variation among laboratory mean values if a common calibrant is used.
In conclusion, the use of a common calibrant significantly affects and improves the accuracy and provides the basis for a proper metrological traceability statement for the certified values in the CRMs. Proper calibration is essential for the comparability of measurement results. For instance, it ensures that production of food/feed can be properly controlled by industry and official testing laboratories; benefiting the European consumer.
Background information on CITAC
The CITAC initiative ("Cooperation on International Traceability in Analytical Chemistry") was founded in 1993 and aims to improve traceability of the results of chemical measurements everywhere in the world and to ensure that analytical measurements made in different countries and/or at different times are comparable. Strategies to realise this objective include amongst others (1) to provide a truly international forum for the exchange of information with respect to worldwide traceability of results of chemical measurements, (2) to play a bridging role between industries, regulatory bodies, universities, metrology, standardisation and accreditation bodies and provide guidance to the analytical community, and (3) to work closely with other international organizations, like CCQM/BIPM, ISO/REMCO, IUPAC, ILAC, AOAC International and regional and national professional chemistry societies and institutions, like EURACHEM and DAC-EuCheMS, using these societies and institutions to act as a conduit to the field laboratories.