title: EC-collaborative study on the determination of aflatoxin B1 in animal feeding stuffs.
abstract: A collaborative study was conducted to test a method, proposed in the European Community (EC) as a candidate-official method for the determination of aflatoxin B1 in compounded feeding stuffs. The study was undertaken on behalf of the European Commission's Community Bureau of Reference (BCR). It involved 25 laboratories from 11 EC countries. The method, based on chloroform extraction and Sep-Pak Florisil and C18 cartridge clean-up, offered either reverse-phase high performance liquid chromatography (HPLC) with iodine post-column derivatization, or two-dimensional thin-layer chromatography (TLC) as determinative steps. In the study, 22 laboratories applied HPLC, three laboratories applied TLC. The study involved six unknown samples. These consisted of blind duplicate samples of compounded feeding stuff, with target concentrations of aflatoxin B1 at less than 2, 8 and and 14 micrograms/kg. Statistical analysis of the HPLC data was carried out according to ISO 5725. For the less than 2 micrograms/kg sample, all reported aflatoxin concentrations were less than 2 micrograms/kg. At the 8 and 14 micrograms/kg level (pooled), repeatability (r) and reproducibility (R), expressed as ratios, were 1.4 and 1.7 respectively, and within-laboratory and between-laboratory coefficients of variation were 11% and 18% respectively. The study revealed that admittance of daylight in the laboratory caused losses of aflatoxin B1 and must be avoided. New glassware coming into contact with aqueous solutions containing aflatoxin B1 was found to be a potential cause of loss of aflatoxin B1. The method has been recommended to the European Commission to be considered for adoption in EC regulations.
authors.affiliation: Laboratory for Residue Analysis, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
authors.forename: H P
authors.initials: HP
authors.lastname: Van Egmond
authors.forename: S H
authors.initials: SH
authors.lastname: Heisterkamp
authors.forename: W E
authors.initials: WE
authors.lastname: Paulsch
mesh_terms: D016604:Aflatoxin B1; D000348:Aflatoxins / Q000032:analysis*; D000704:Analysis of Variance; D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D005062:European Union; D005506:Food Contamination / Q000032:analysis*; D015203:Reproducibility of Results
chemical_list: D000348:Aflatoxins; D016604:Aflatoxin B1