title: Feed premix: a difficult matrix for the accurate determination of trace elements - the outcome of IMEP-114 and IMEP-36.
abstract: This paper presents the outcome of two proficiency tests (IMEP-114/36) running in parallel, which focused on the determination of total As, Cd, Pb, Hg and Sn in feed premixes. Both exercises aimed to test the performance of laboratories measuring trace elements in feed, in compliance with Directive 2002/32/EC of the European Parliament and of the Council on undesirable substances in animal feed. IMEP-114 was run for the European Union National Reference Laboratories, while IMEP-36 was open to all food control laboratories that wished to participate. In total 80 laboratories from 37 countries registered to both proficiency tests, from which 75 laboratories reported results. The test material used in this exercise was commercially available feed premix, which was processed, bottled, labelled and dispatched to participants. The performance of the participating laboratories was similar in both proficiency tests and was very good in the case of total Cd and less satisfactory for total As and total Pb. For total Sn only one-third of the participants reported results, from which 33% performed satisfactorily. Thirty-four participants reported results for total Hg, although the expert laboratories stated that the mass fraction for that measurand was below the limit of detection of the method used. An evaluation of the reasons that could be at the basis of unsatisfactory results has been carried out and is presented here.
authors.affiliation: a European Commission , Directorate General Joint Research Centre, Institute for Reference Materials and Measurements , Geel , Belgium.
authors.forename: Yiannis
authors.initials: Y
authors.lastname: Fiamegos
authors.forename: Fernando
authors.initials: F
authors.lastname: Cordeiro
authors.forename: Piotr
authors.initials: P
authors.lastname: Robouch
authors.forename: Håkan
authors.initials: H
authors.lastname: Emteborg
authors.forename: Jean
authors.initials: J
authors.lastname: Charoud-Got
authors.forename: Lars-Gunnar
authors.initials: LG
authors.lastname: Omberg
authors.forename: Ilia
authors.initials: I
authors.lastname: Rodushkin
authors.forename: Beatriz
authors.initials: B
authors.lastname: de la Calle
mesh_terms: D000821:Animal Feed / Q000032:analysis* / Q000633:toxicity; D000818:Animals; D001151:Arsenic / Q000032:analysis / Q000633:toxicity; D002104:Cadmium / Q000032:analysis / Q000633:toxicity; D002417:Cattle; D005062:European Union; D005506:Food Contamination / Q000032:analysis*; D059022:Food Safety; D064088:Hazard Analysis and Critical Control Points / Q000379:methods; D007753:Laboratories / Q000592:standards; D007854:Lead / Q000032:analysis / Q000633:toxicity; D008628:Mercury / Q000032:analysis / Q000633:toxicity; D019216:Metals, Heavy / Q000032:analysis* / Q000633:toxicity; D015203:Reproducibility of Results; D014001:Tin / Q000032:analysis / Q000633:toxicity; D014131:Trace Elements / Q000032:analysis* / Q000633:toxicity
chemical_list: D019216:Metals, Heavy; D014131:Trace Elements; D002104:Cadmium; D007854:Lead; D014001:Tin; D008628:Mercury; D001151:Arsenic