Metrological Assurance of Dioxin Measurements. A Certified Reference Material for Measuring the Dioxin Mass Fraction in Animal Fat

This article presents information on the development of a new type of certified reference material (CRM) of the mass fraction of dioxins in animal fat, assured with metrological traceability. A procedure for preparing and certifying the CRM is provided. GC-LRMS in combination with isotopic dilution was used as an analytical method for establishing certified characteristics. The uncertainties induced by the CRM inhomogeneity and instability were estimated in order to account for their contribution to the combined uncertainty of the obtained certified values. In addition, the results of interlaboratory comparisons (ILC) studies for an experimental batch of the developed CRM are presented. Measurement results provided by ILC participants are shown to be in good agreement with the certified characteristics of the CRM. The certified values of the mass fractions of dioxins (PCDF group) in the CRM are established to vary from 1 to 1000 ng/kg, with the relative expanded uncertainty ranging from 10 to 20%.