Inter-laboratory comparison of an analytical method for the determination of the feed additive semduramicin in poultry feed at authorised level by liquid chromatography single quadrupole mass spectrometry

Abstract

A collaborative study was carried out according to internationally recognised guidelines in order to establish the performance characteristics of an LC/MS method for the determination of the feed additive semduramicin (SEM) in poultry feed at the level (20–25 mg kg⁻¹) authorised within the European Union. Fifteen laboratories participated in the validation study, and all reported results. The content of SEM in the tested materials, provided as blind duplicates, ranged from 11.5 mg kg⁻¹, which corresponds to half the mean authorised level, to 45.0 mg kg⁻¹, which corresponds to twice the mean authorised level. All the materials were analysed by the participating laboratories using two different quantification approaches: standard addition and external standard calibration. The relative standard deviation of reproducibility (RSD_R) for both quantification approaches varied from 8% to 18%, corresponding to HORRAT values ranging from 0.8 to 1.5, which were therefore in all cases below the critical value of 2.0. Consequently, the proposed analytical method and both quantification approaches can be considered to be fully validated and transferable to the control laboratories and applied for the determination of SEM in poultry compound feed at authorised level within the frame of official control. Further steps in the administrative procedure aiming to adopt the method as part of an ISO/CEN standard are currently ongoing.

Keywords:

• inter-laboratory validation
• liquid chromatography/mass spectrometry
• feeding
• additives general
• animal feedingstuffs

Acknowledgements

The authors would like to thank all the participants for their contribution to the assay as well as for their fruitful feedback regarding the method: AGES-CC TAHO (Vienna, Austria); Bundesinstitut für Risikobewertung (BfR) (Berlin, Germany); CCTIA (Bratislava, Slovakia); Central Agricultural Office, Food and Feed Safety Directorate; Feed Investigation National Reference Laboratory (Budapest, Hungary); Central Institute for Supervising and Testing in Agriculture National Reference Laboratory-Regional Department Praha (Motol, Czech Republic); CER Groupe. Labo Hormonologue (Marloie, Belgium); Chemisches und Veterinäruntersuchungsamt Ostwestfalen-Lippe (Detmold, Germany); Eurofins Food & Agro Sweden AB (Lidköping, Sweden); Futtermittelinstitut Stade (Stade, Germany); Laboratori Agroalimentari (Cabrils, Spain); Landwirtschaftliche Untersuchungs- und Forschungsanstalt Speyer (Spreyer, Germany); LGL (Oberschleißheim; Germany); LUFA Nord-west Hameln (Hameln, Germany); National Veterinary Research Institute, Department of Pharmacology and Toxicology (Pulawy, Poland); RIKILT-Institute of Food Safety (Wageningen, the Netherlands); Thüringer Landesanstalt für Landwirtschaft (TLL) (Jena, Germany) and VITO (Mol, Belgium). The authors are grateful to Phibro Animal Health s.r. for kindly providing a sufficient amount of the SEM standard fulfilling the requirements for this type of assay. They are also grateful to the European Commission for founding this study, to the European Committee for Standardisation CEN/TC 327/WG 3: Animal feedingstuffs – ‘Feed Additives and Drugs’ for its scientific input, and to the Netherlands Standardization Institute (NEN) for its help with all administrative issues related to the project. The authors are grateful to Federica Serano for performing the grinding and packaging of the test materials used within this collaborative study.