Development of a Matrix Certified Reference Material for Quantification of Aflatoxin B1 in Peanut Oils

Aflatoxin B1 in a peanut oil matrix certified reference material (CRM, GBW10176) has been issued for accurate determination of aflatoxin B1 in real samples. This matrix CRM was prepared from commercial peanut oils naturally contaminated by aflatoxin B1, with the aid of a liquid–liquid extraction process. Specially, the certified value of CRM was determined using two individual approaches, liquid chromatography–isotope dilution tandem mass spectrometry and standard addition liquid chromatography–fluorescence detection techniques. More importantly, assessments of homogeneity and short- and long-term stabilities confirmed that the GBW10176 CRM was sufficiently homogeneous between packages or within package, and it could be stable up to 7 days stored below 50 °C or 18 months at 4 °C. The metrological traceability of GBW10176 was ensured by the application of pure aflatoxin B1 (GBW10172). Its uncertainty was evaluated with the contributions from the characterization, homogeneity, and stability. Resultantly, the certified value of the aflatoxin B1 CRM (GBW10176) was 23.4 μg/kg with an uncertainty of 3.1 μg/kg (k = 2).