IMEP-40: Determintion of trace elements in seawater

Fifty-three participants from twenty-nine countries registered to the exercise. Seven participants did not report results. The test item used was a seawater sample containing the trace elements As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se and Zn. Laboratories with demonstrated experience in the field provided results to establish the assigned values (Xref). The standard uncertainties associated to the assigned values (uref) were calculated according to ISO Guide 35. Laboratory results were rated with z- and zeta (ζ-) scores in accordance with ISO 13528. The standard deviation for the proficiency assessment, , for all elements was based on the experience in the Water Framework Directive and was set at 25 %. The trace elements were present in very low concentration levels (low μg L-1 range equal to natural contamination levels) and therefore many laboratories reported "lower than" values. The percentage of satisfactory z-scores ranged from 41 % (Cr, Fe) to 86 % (Mo). The low concentration levels of the trace elements in a difficult matrix (high saline content) need to be taken into consideration to understand the general low rate of satisfactory scores. Laboratories that score systematically too high should examine the cause of this positive bias.JRC.D.5-Standards for Food Bioscienc

IMEP-42: Determination of PFASs in fish

The Institute for Reference Materials and Measurements of the Joint Research Centre, a Directorate General of the European Commission (EC-JRC-IRMM) operates the International Measurement Evaluation Programme (IMEP). It organises interlaboratory comparisons (ILC's) in support to European Union (EU) policies. This report presents the results of a proficiency test (PT), IMEP-42, on the determination of perfluoroalkyl substances (PFASs) in fish tissue. The exercise was organised in support to the Commission Recommendation 2010/161/EU on the monitoring of perfluoroalkylated substances in food and the Water Framework Directive 2000/60/EC. Seventeen participants from thirteen countries registered to the exercise and all of them reported results. The test item was fish tissue (pike-perch) containing perfluoroalkyl carboxylates as perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), perfluorotridecanoic acid (PFTrDA) or perfluorotetradecanoic acid (PFTeDA); perfluoroalkyl sulfonates as perfluorohexanesulfonate (PFHxS), linear perfluorooctane sulfonate (L-PFOS) or branched perfluorooctane sulfonate (br-PFOS); and, perfluoroalkyl sulphonamides as perfluorooctane sulphonamide (FOSA). The test item was a candidate certified reference material (CRM) produced by IRMM under ISO Guide 34 accreditation and in line with ISO Guide 35. Laboratories with demonstrated experience in the field provided results to establish the assigned values (Xref). The standard uncertainties associated to the assigned values (uref) were calculated according to the ISO Guide 35 by combining the uncertainty of the characterisation (uchar) with a contribution for homogeneity (ubb) and for stability (ust). Laboratory results were rated with z- and zeta (ζ-) scores in accordance with ISO 13528. The standard deviation for the proficiency assessment, σ ̂, for all elements was set at 25 % of the respective assigned value. The overall performance in this PT was good even though analyte dependent. High rates (78% - 100%) of satisfactory performances expressed as z-scores ≤ 2 were obtained for L-PFOS, PFDA, PFUnDA, PFDoDA, tot-PFOS and FOSA while the lowest rates of satisfactory performances (50%) were obtained for br-PFOS and PFTrDA. Many "less than X" values were reported for the three PFASs that could not be scored due to the high uncertainty on the assigned value (PFNA, PFTeDA and PFHxS). The results in this PT showed that the sensitivities of the methods used by the participants were fit for the purpose of measuring the legal limits set in legislation.JRC.D.5-Standards for Food Bioscienc

IMEP-37: Determination of pesticides in grapes - Interlaboratory Comparison Report

This report presents the results of a proficiency test exercise (PT) which focussed on the determination of pesticides in grapes in support of Regulation 396/2005/EC of the European Parliament and of the Council on maximum residue levels of pesticides in or on food and feed of plant and animal origin. Eighty-seven participants from thirty-three different countries registered to the exercise, of which eighty-one reported results. From these eighty-one participants, forty were from EU countries while forty-one were from outside the EU. The test item was a grapes sample spiked with 20 selected pesticides. The assigned values were obtained as the average of results reported by five expert laboratories having demonstrated experience in the analysis of pesticides in vegetable and fruit matrices. The standard uncertainties related to the assigned values (Uref) were calculated by combining the uncertainty of the characterisation (Uchar) with a contribution for homogeneity (Ubb) and for stability (Ust). Uchar was calculated following the ISO guide 35. Laboratory results were rated with z- and zeta (ζ-) scores in accordance with ISO 13528 and ISO 17043. The z-score compares the participant's deviation from the reference value with the standard deviation for proficiency assessment (σp) used as common quality criterion, the ζ-score states if the laboratory result agrees with the assigned value within the respective uncertainty. The standard deviation for the proficiency assessment, σp, was set by the advisory board of this PT at 25% for the 20 measured pesticides based on previous experience with similar measurands. Participants were not scored for triadimenol due to the large Uref associated to the assigned value. According to the results obtained in the frame of the IMEP-37 study, the participants performed satisfactorily for the 19 scored pesticides ranging from 81 % (carbendazim) to 97 % (azoxystrobin, penconazole, pyrimethanil) of satisfactory z-scores. When analysing the results of the group of non-EU countries separately, similar results were obtained. It can be concluded that the performance in this PT is satisfactory for the laboratories world-wide.JRC.D.5-Standards for Food Bioscienc

IMEP-38: Determination of total As, Cd, Pb, and Hg in compound feed - Interlaboratory Comparison Report

The Institute for Reference Materials and Measurements (IRMM) of the Joint Research Centre, a Directorate General of the European Commission, operates the International Measurement Evaluation Programme (IMEP). IMEP organizes interlaboratory comparisons (ILCs) in support to EU policies. This report presents the results of the proficiency test (PT) which focused on the determination of total As, Cd, Pb and Hg in compound feed according to Directive 2002/32/EC of the European Parliament and of the Council on undesirable substances in animal feed. The IMEP-38 exercise was organized aiming to assess the performance of food and feed control laboratories and official control laboratories. The test material used in this exercise was commercially available compound feed for cats which after the appropriate processing was spiked, bottled, labelled, numbered accordingly and dispatched to the participants on the 27th of June 2013. Forty-seven laboratories from 24 countries registered to the exercise of which 44 reported results and answered the respective questionnaire. The percentage of satisfactory z-scores ranged from 58 % (total arsenic) to 74 % (total cadmium) and the ζ-scores obtained were lower by 10 to 21%.JRC.D.5-Standards for Food Bioscienc

Determination of total As, Cd, Pb and Hg in vegetable feed: IMEP-119 Proficiency Test Report

This report presents the results of a PT (IMEP-119) of the EURL-HM focussing on the determination of total As, Cd, Pb and Hg in vegetable feed in support to Directive 2002/32/EC of the European Parliament and of the Council on undesirable substances in animal feed. IMEP-119 was also opened to all laboratories who wish to take part in the exercise as a way to benchmark their performance against NRLs and other laboratories. One hundred and two participants from 45 countries registered to the exercise. Only eight participants did not report their results. Laboratory results were rated using z- and zeta (ζ-) scores in accordance with ISO 13528. The relative standard deviation for proficiency assessment was set to 15 % for the total As, Cd and Pb mass fractions, and to 22 % for the total Hg mass fraction, respectively. An overall adequate performance for NRLs and feed control laboratories is shown by the percentage of satisfactory performance (expressed as z-scores). These percentages were ranging from 93 to 74 % for NRLs and from 92 to 69 %, for feed control laboratories, respectively.JRC.D.5-Standards for Food Bioscienc

EURL-HM-22 Proficiency test report: Determination of total As, Cd, Pb, Hg, MeHg and inorganic As in fish

The European Union Reference Laboratory for Heavy Metals in Feed and Food (EURL-HM) organised a proficiency test (EURL-HM-22) for the determination of total As, Cd, Pb, Hg and inorganic As (iAs) in fish to support the Commission Regulation (EC) 1881/2006 setting maximum levels for certain contaminants in foodstuffs. This PT was open only to National Reference Laboratories (NRLs). The reference material "IAEA-436" (Tuna fish flesh homogenate) was used as test item. The finely ground dry powder material was rebottled, relabelled and dispatched to the participants. The reference values of interest were provided by the IAEA, together with an informative value for total Pb. The University of Graz (Austria) was requested to analyse the mass fraction of iAs in the material and reported a truncated value ("less than" 0.005 mg kg-1). Forty two participants from 30 countries registered to the exercise (all EU Member States plus Iceland and Norway). Only one participant could not report results due to technical instrumental problems. Laboratory results were rated using z- (z'- for MeHg) and zeta scores in accordance with ISO 13528:2015. The following relative standard deviations for proficiency assessment (σpt) were set according to the modified Horwitz equation: 13% for total Hg and MeHg; 15% for total As; and 22% for total Cd. No scoring was provided for total Pb and iAs. More than 92% of the participating NRLs reported satisfactory results (according to the z-score) for total As, Cd, Hg and MeHg, thus confirming their ability in monitoring the maximum levels set by the European Regulation (EC) No 1881/2006 for fish commodities. However, only 9 (out of 41) participants reported results for MeHg. Most of the laboratories provided realistic estimates of their measurement uncertainties.JRC.F.5-Food and Feed Complianc

EURL-FA Control: Proficiency Test Report

The European Union Reference Laboratory for Feed Additive Control (EURL-FA Control) organised a proficiency test (PT) for the determination of the mass fraction of total selenium in compound feed, to support the Commission Directive 86/403/EEC concerning additives in feeding stuffs. This proficiency test was open to National Reference Laboratories (NRLs) and official feed control laboratories (OCLs). The material used as test item was a commercially available compound feed for rabbits (containing, among others, selenium as sodium selenite) which, after appropriate processing, was bottled, labelled and dispatched to participants on May 22, 2018. The homogeneity and stability of the test item were evaluated and the assigned values were derived from the results reported by the selected expert laboratories. Twenty one NRLs and four OCLs from 20 countries - representing several EU Member States, Norway and Switzerland - registered to the exercise and reported results at the end of June 2018. Laboratory results were rated using z' and ζ (zeta) performance scores in accordance with ISO 13528:2015. The relative standard deviation for proficiency assessment (σpt) of 15 % of the assigned value was derived from the reproducibility standard deviation reported in the CEN standard EN 16159:2012. Twenty three (out of 25) laboratories reported satisfactory results (according to the z' score). This confirms the ability of most NRLs in monitoring maximum levels set by the Commission Directive 86/403/EEC concerning additives in feeding stuffs.JRC.F.5-Food and Feed Complianc

Total cow’s milk protein in cookies: the first interlaboratory comparison with a well-defined measurand fit for food allergen risk assessment

A feasibility interlaboratory comparison (ILC) was organised by the European Commission’s (EC) Joint Research Centre (JRC) on the determination of the mass fraction of total cow’s milk protein in baked cookies. The ILC was organised to support Commission Regulation (EU) 1169/2011 on the provision of food information to consumers, including the mandatory allergen food labelling and the harmonisation of measurement procedures used for food allergen analysis. An incurred baked cookie was prepared at the JRC and samples were sent to participants for analysis. The laboratories were asked to report their results as “mass fraction of total cow’s milk protein in baked cookies”. This common well-defined measurand was used for the first time in such an ILC to assess the equivalence of measurement results. Homogeneity and stability of the test material were demonstrated to be adequate. An indicative assigned value was established using the JRC single-laboratory validated method based on liquid chromatography coupled to mass spectrometry (LC–MS), independently from the results reported by the participants. Twenty-three laboratories from the European Network of Food Allergen Detection Laboratories (ENFADL), representing 20 European Union (EU) Member States, reported results. Their laboratory performance was assessed using the percent difference Di score. The participating laboratories applied either enzyme-linked immunosorbent assays (ELISA) or LC–MS. Even though the majority of the laboratories used commercially available ELISA test kits, a significant scatter of all the reported results was observed. This indicates that further harmonisation is required for measurement procedures aiming to determine potentially allergenic constituents in food

Application of the CEN/ISO Standard for Phytase Activity Measurements to a New Phytase Product: Determination of a Robust Conversion Factor by an Interlaboratory Study for Screening Feed Samples

Background: Phytase-based preparations are important feed additives currently authorised in the European Union (EU). The ISO standard 30024 describes a harmonised method for the determination of the phytase activity and is fit-for-purpose for official control of a group of phytase products. However, it is not suitable for the determination of the phytase activity of a new feed additive encoded as 4a16 in the European Union Register of Feed Additives, to wich a slightly different phytase activity definition has been attributed. Objective: To establish a robust conversion factor to support official control laboratories that apply the ISO method when monitoring feed products containing the 4a16. Methods: The phytase activity of test materials was determined by the participants by using the ISO and/or the 'applicant' methods. Results: Robust standard deviations for repeatability and for reproducibility of the methods applied for the determination of the phytase activity in the materials containing the 4a16 feed additive ranged from 2.4 % to 17 % (ISO method) and from 7.7 % to 39 % ('applicant' method). Conclusions: The data obtained confirmed the performance characteristics published for other phytase-based feeds in the related standard methods. These results allowed to estimate a factor of 2.68 to convert phytase activities measured with the ISO method into the enzyme activity measured with the 'applicant' method. Highlights: The obtained conversion factor will allow EU official laboratories to screen feed samples supplemented with the 4a16 phytase by applying the ISO standard 30024.JRC.F.5-Food and Feed Complianc

Determination of total As, Cd, Pb, Hg, Sn and inorganic As in canned food IMEP-118 Proficiency test Report

This report presents the outcome of the proficiency test, on the determination of total As, Cd, Pb, Hg, Sn and iAs in canned food (peas in brine). The exercise was organised by the European Union Reference Laboratory for Heavy Metals (EURL-HM) to support the Commission Regulation (EC) 1881:2006 setting maximum levels for certain contaminants in foodstuffs. Participation in the proficiency test was mandatory for the nominated NRLs, and open to other OCLs and interested laboratories. A total of 127 participants from 36 countries registered to the exercise. All NRLs (36) reported results, while 4 non-NRL participants did not. From the participating laboratories 54 % analysed the drained product and 46 % the solid/liquid composite. Hence, a nonunified analytical approach is observed. The majority of laboratories (more than 74 %) reported satisfactory results for the five scored measurands with measurable concentrations (total As, Cd, Pb, Sn and iAs). The best performances were obtained for total As, Cd and Pb. The interpretation of the respective legislation is not straightforward as indicated by the 32 laboratories that characterised the test item as compliant with the legislation, although it was not.JRC.D.5-Standards for Food Bioscienc