Certification of different mass fractions of DP202216 in maize seed powder : ERM®-BF444c, ERM®-BF444d and ERM®-BF444e

ERM®-BF444c, ERM®-BF444d and ERM®-BF444e are three matrix materials certified for the mass fraction of DP202216 maize (unique identifier DP-2Ø2216-6), produced within the scope of ISO 17034 accreditation [1]. Genetically modified (GM) maize seeds of the DP202216 event and seeds from a non-GM maize variety were milled, sieved and dried to obtain GM and non-GM seed powders. Mixtures were produced from these pure powders and certified for their DP202216 mass fractions. The reference materials are available in glass vials containing at least 1 g of dried maize powder sealed under an atmosphere of argon. Between-unit homogeneity was quantified and stability was assessed in accordance with ISO 33405:2024 [2]. The minimum sample size for one measurement is 200 mg. The certified value was obtained from the gravimetric preparations, taking into account the purity of the base materials and their water mass fractions. The certified values were confirmed by event-specific real-time PCR measurements performed within the scope of accreditation to ISO/IEC 17025:2017 [3]. Uncertainties of the certified values were calculated in accordance with ISO 17034:2016 [1] and ISO 33405:2024 [2] and include uncertainties related to possible inhomogeneity, instability and characterisation. The materials are intended for the calibration or quality control of methods for the identification and quantification of genetically modified DP202216 maize in food and feed. The certification project was subjected to peer-review involving internal experts.