Report of the Second Interlaboratory Comparison Organised by the Community Reference Laboratory for Heavy Metals in Feed and Food: 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 of the IRMM. The samples were dispatched on the first half of May 2007. Each participant received two sets of samples containing one bottle per set. Each bottle contained approximately 100 mL of 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 combining the uncertainty of the spiking procedure with a contribution for the between-bottle homogeneity and for long-term stability of the test material. Participants were invited to report the uncertainty on their measurements. This was done by all them. Laboratory results were rated with z and zeta scores in accordance with ISO 135281. Standard deviation for proficiency assessment (also called target standard deviation) for Cd, Pb and Hg was 10% of the assigned value.JRC.D.4-Isotope measurement

Report of the Third Interlaboratory Comparison Organised by the Community Reference Laboratory for Heavy Metals in Feed and Food - Total Cd, Pb and Hg and Extractable Cd and Pb in Feed

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 its core tasks is to organise interlaboratory comparisons (ILCs) among appointed National Reference Laboratories (NRLs). This report presents the results of the third ILC of the CRL-HM which focused on the determination of total Cd, Pb and Hg and extractable Cd and Pb in feed according to Directive 2002/32/EC of the European Parliament and of the Council on undesirable substances in animal feed. The test material used in this exercise was a commercial compound feed for fish provided by the Centro di Referenza Nazionale per la Sorveglianza e il Controllo degli Alimenti per Animali, Istituto Zooprofilattico del Piemonte. The material, naturally contaminated, was processed, bottled, labelled and dispatched by the Reference Materials Unit of the IRMM. The samples were dispatched on the second half of October 2007. Each participant received one bottle containing approximately 20 g of test material. Thirty-one participants from 25 countries registered to the exercise of which 31 submitted results for total Cd and total Pb, 28 for total Hg, 26 for extractable Cd and 24 for extractable Pb. The assigned values (Xref) were provided by IRMM using isotope dilution-inductively coupled plasma-mass spectrometry (ID-ICP-MS). The analytical uncertainty of Xref, uchar, was calculated according to the ISO Guide to the Expression of Uncertainty in Measurement (GUM)2. Homogeneity and stability studies were subcontracted to Bundesanstalt für Materialforschung und ¿Prüfung (BAM). The uncertainties of the respective assigned values, uref, were calculated combining the analytical uncertainty, uchar, with a contribution for the between-bottle homogeneity, ubb, and for the short term stability of the test material, usts. Participants were invited to report the uncertainty on their measurements. This was done by 29 laboratories for total Cd, 23 for total Pb, 25 for total Hg, 18 for extractable Cd and 13 for extractable Pb. Laboratory results were rated with z and zeta scores in accordance with ISO 135283. Standard deviation for proficiency assessment (also called target standard deviation) were calculated using the modified Horwitz equation and were 22 % of the assigned value for total Pb and Hg and for extractable Pb and 16 % of the assigned value for total and extractable Cd.JRC.D.4-Isotope measurement

IMEP-22 Sulphur in Petrol

EU Directive 2003/17/EC lays down requirements for the sulphur content in automotive petrol and provides criteria for appropriate methods of analysis to monitor compliance with these requirements.IMEP-22 studies whether the laboratories involved in petrol analysis in the frame of EU legislation are able to measure a sulphur content of 20.5 mg·kg-1. This value was certified by IRMM using a primary method of measurement. Involved in this interlaboratory comparison are also DG TAXUD and the European co-operation for Accreditation EA.JRC.D.4-Isotope measurement

IMEP-23: The Eight WFD PAHs in Water in Presence of Humic Acid

IMEP-23 is linked to the Water Framework Directive (WFD). It studied the capability of control laboratories to measure the eight WFD PAHs in the presence of humic acid in a water matrix. Humic acid simulates natural colloidal organic matter and is known to adsorb PAHs. This gives rise to various issues that are of large importance for the control laboratories. Participants' results were benchmarked against the IMEP certified reference values. On average 80 % of the z scores was satisfactory. Zeta scores were calculated for those laboratories who provided an uncertainty estimate. These were less satisfactory and this shows that many laboratories encounter difficulties to provide a reasonable uncertainty estimate.JRC.D.4-Isotope measurement