Report of the Proficiency Test “FAC-25/01”
The European Union Reference Laboratory for Feed Additives ‘Control’ (EURL-FA Control) organised a proficiency test (FAC-25/01) for the determination of the total mass fraction of Cu, Fe, Mn and Zn in compound feed, to support Regulation (EU) 2017/625 [1] on official controls and Commission Implementing Regulations (EU) No 2017/2330 [2], 2017/1490 [3], 2018/1039 [4] and 2016/1095 [5] authorising respectively iron, manganese, copper and zinc as feed additives for all animal species. 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 pig containing, among others, Cu (3b405, Copper (II) Sulphate Pentahydrate), Fe (3b103, Iron (II) sulphate monohydrate), Mn (3b502, Manganese (II) Oxide) and Zn (3b605, Zinc Sulphate, Monohydrate). The pelleted material was milled, homogenised, placed under vacuum in labelled aluminium bags and dispatched to participants. The EURL assessed the homogeneity and stability of the test item, and established the assigned value based on the consensus of three expert laboratories. An assigned value for iron could not be established because of the large scatter observed among the results from the three expert laboratories.
Nineteen NRLs and nine OCLs from sixteen EU Member States and Switzerland registered to the exercise and all but one reported results within the given deadline. Laboratory results were rated using z, z’ and ζ (zeta) performance scores in accordance with ISO 13528:2022 [6]. For Fe, Mn and Zn a relative standard deviation for proficiency assessment (σpt) of 15 % of the assigned value was used; for Cu, present at lower concentration, a σpt of 20 % was selected. The decision was derived from the reproducibility standard deviation reported in standard methods and from the experience acquired in similar previous PT rounds.
The totality of the reported results demonstrated satisfactory performance according to the z or z’ scores. This confirms the capability of NRLs and OCLs to accurately monitor the total mass fraction of Cu, Fe, Mn and Zn in compound feed.
SERANO Federica;
BOUTEN Katrien;
DEHOUCK Pieter;
GARCIA DIEZ Raul;
EZERSKIS Zigmas;
ROBOUCH Piotr;
SNELL James;
STROH Aneta;
STROKA Joerg;
VAN BRITSOM Geert;
2025-11-28
Publications Office of the European Union
JRC144078
978-92-68-34515-3 (online),
1831-9424 (online),
EUR 40560,
OP KJ-01-25-610-EN-N (online),
https://publications.jrc.ec.europa.eu/repository/handle/JRC144078,
10.2760/8044879 (online),
