The certification of the aflatoxin mass fractions in peanut butter

Abstract

In the context of control activities contamination of food and feed with aflatoxins is a frequently observed non compliance. Pistachios, peanuts and products thereof are particularly affected. The Institute for Reference Materials and Measurements has therefore produced a peanut butter material certified for its aflatoxin mass fractions. This certified reference material (CRM) allows for the evaluation of analytical method performance and the assessment of the comparability of results from different laboratories. The CRM was produced using naturally contaminated raw materials to ensure equivalent behaviour compared to samples routinely encountered. The homogeneity and stability of the CRM were thoroughly tested and certified values were determined in an inter-laboratory study. Furthermore, uncertainties of the certified values were assessed including contributions of the homogeneity, stability and certification studies to the combined uncertainty. This newly prepared CRM allows an assessment of trueness of the analytical method at a concentration level corresponding to the legal limits enforced in the European Union. The material has the following certified properties: aflatoxin B1 1.77±0.29 µg/kg, aflatoxin B2 0.48±0.07 µg/kg, aflatoxin G1 0.9±0.4 µg/kg, aflatoxin G2 0.31±0.12 µg/kg and total aflatoxins, as sum of aflatoxins B1, B2, G1 and G2, 3.5±0.5 µg/kg.