title: Uncertainty from sampling in measurements of aflatoxins in animal feedingstuffs: application of the Eurachem/CITAC guidelines.
abstract: The duplicate method for estimating uncertainty from measurement including sampling is presented in the Eurachem/CITAC guide. The applicability of this method as a tool for verifying sampling plans for mycotoxins was assessed in three case studies with aflatoxin B(1) in animal feedingstuffs. Aspects considered included strategies for obtaining samples from contaminated lots, assumptions about distributions, approaches for statistical analysis, log(10)-transformation of test data and applicability of uncertainty estimates. The results showed that when duplicate aggregate samples are formed by interpenetrating sampling, repeated measurements from a lot can be assumed to approximately follow a normal or lognormal distribution. Due to the large variation in toxin concentration between sampling targets and sometimes very large uncertainty arising from sampling and sample preparation (U(rel) ≥ 50%), estimation of uncertainty from log(10)-transformed data was found to be a more generally applicable approach than application of robust ANOVA.
authors.affiliation: University of Veterinary Medicine, Institute of Animal Nutrition, Veterinärplatz 1, 1210 Vienna, Austria. e.v.reiter@gmx.at
authors.forename: Elisabeth Viktoria
authors.initials: EV
authors.lastname: Reiter
authors.forename: Mike Francis
authors.initials: MF
authors.lastname: Dutton
authors.forename: Ali
authors.initials: A
authors.lastname: Agus
authors.forename: Erik
authors.initials: E
authors.lastname: Nordkvist
authors.forename: Mulunda Feza
authors.initials: MF
authors.lastname: Mwanza
authors.forename: Patrick Berka
authors.initials: PB
authors.lastname: Njobeh
authors.forename: Deni
authors.initials: D
authors.lastname: Prawano
authors.forename: Per
authors.initials: P
authors.lastname: Häggblom
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Razzazi-Fazeli
authors.forename: Jürgen
authors.initials: J
authors.lastname: Zentek
authors.forename: Mats Gunnar
authors.initials: MG
authors.lastname: Andersson
mesh_terms: D000348:Aflatoxins / Q000032:analysis*; D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D000348:Aflatoxins