CERTIFICATION REPORT: The certification of different mass fractions of Bt11 in maize powder: Certified Reference Materials: ERM®-BF412ak, ERM®-BF412bk, ERM®-BF412ck, ERM®-BF412dk and ERM®-BF412ek

Abstract

This report describes the production of a set of Certified Reference Materials (CRMs), ERM-BF412ak, bk, ck, dk and ek, which are certified for their Bt11 maize (unique identifier SYN-BTØ11-1) event mass fractions. These materials were produced following ISO Guide 34:2009 and are certified in accordance with ISO Guide 35:2006. Genetically modified (GM) maize seeds of the Bt11 event and seeds from a non GM maize variety were milled to obtain GM and non-GM seed powders with a similar particle size distribution. Mixtures of non-GM and GM maize seed powder were prepared gravimetrically. The certified values were obtained from the gravimetric preparations, taking into account the water mass fractions of the two powder materials and the genetic purity with respect to the Bt11 maize. The certified values were confirmed by event-specific real-time PCR as an independent verification method (measurements were within the scope of accreditation to ISO/IEC 17025:2005). The uncertainties of the certified values were estimated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties relating to possible inhomogeneity (Section 4), instability (Section 5) and characterisation (Section 6). The materials are intended for the calibration or quality control of real-time PCR measurements to identify Bt11 maize and quantify its mass fraction. As with any reference material, they can also be used for establishing control charts or for carrying out validation studies. The CRMs are available in glass bottles containing at least 1 g of dried maize seed powder, sealed under an atmosphere of argon. The minimum amount of sample to be used for extraction of the DNA is 200 mg.JRC.F.6-Reference Material