The certification of different mass fractions of the GM event 73496 in rapeseed powder : Certified Reference Materials ERM-BF434a, ERM-BF434b, ERM-BF434c, ERM-BF434d and ERM-BF434e

This report describes the production of the set of Certified Reference Materials (CRMs) ERM-BF434a, b, c, d and e. These are matrix materials certified for their 73496 rapeseed mass fractions. Materials have been produced following ISO Guide 34:2009. Genetically modified (GM) rapeseeds of the event 73496 and of a non-GM rapeseed variety were ground to obtain GM and non-GM starting materials. Gravimetric mixtures of non-GM and GM rapeseed powder were prepared by dry-mixing. The between unit-heterogeneity has been quantified and stability during dispatch (short-term stability) and stability during storage (long-term stability) have been assessed in accordance with ISO Guide 35:2006. The certified value was obtained from the gravimetric preparations, taking into account the purity of the seeds used for the processing of the materials and their respective water mass fraction. The certified values were confirmed by event-specific real-time PCR as an independent verification method (measurements within the scope of accreditation to ISO/IEC 17025:2005). Uncertainties of the certified values were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties related to possible inhomogeneity (Section 4), instability (Section 5) and characterisation (Section 6). The materials are intended for the calibration or quality control of 73496 rapeseed identification and quantification measurements expressed in mass fractions. As any reference material, they can also be used for control charts or validation studies. The CRMs are available in glass vials containing at least 1 g of dried rapeseed powder closed under argon atmosphere. The minimum amount of sample to be used is 200 mg. The CRM has been accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium.