Report of the second interlaboratory comparison, Total Cd, Pb and Hg in mineral water
The institute for Reference Materials and Measurements (IRMM) of the European Commission's Directorate-General Joint Research Centre holds the Community Reference Laboratory for Heavy Metals in Feed and Food (CRL-HM). One of the core tasks is to organise interlaboratory comparisons (ILCs) among appointed National Reference Laboratories (NRLs). This report presents the results of the second ILC of the CRL-HM which focused on the determination of the total Cd, Pb and Hg content in mineral water. The test material used in this exercise was a commercial mineral water purchased in Belgium at a local supermarket. The material was spiked with Cd, Pb and Hg, rebottled and dispatched by the Reference Material Unit (RM) of the IRMM. The samples were dispatched on the first half of May 2007. Each participant received two sets of samples containing one bottle each set. The content of the bottle was approximately 100 mL of the test material. Twenty participants from 17 countries registered to the exercise of which 20 submitted results for Cd and Pb and 19 for Hg. The assigned values were those obtained from the gravimetric measurements used to spike the material. The homogeneity and stability studies were subcontracted to the University of Natural Resources and Applied Life Sciences (BOKU) in Vienna. The uncertainty of the assigned values was calculated by combining the uncertainty of the spiking procedure with a contribution for the between-bottle homogeneity and a contribution for the stability of the test material. Participants were invited to report the uncertainty on their measurements. This was done by all the participants. Laboratory results were rated with z and zeta scores in accordance with ISO 13528i. Standard deviation for proficiency assessment (also called target standard deviation) for Cd, Pb and Hg was 10% of the assigned value.
Bibliographic Reference: EUR 22870 EN (2007), 32 pp. Free of charge
Availability: Katalogue Number: LA-NA-22870-EN-C The PDF version can be downloaded from: http://bookshop.europa.eu
ISBN: ISBN 978-92-79-06473-9
Record Number: 200819813 / Last updated on: 2008-05-05
Original language: en
Available languages: en