The certification of reference materials of dry-mixed maize powder with different mass fractions of GA21 roundup ready® maize : certified reference materials IRMM-414 (IRMM-414-0/IRMM-414-1/IRMM-414-2/IRMM-414-3/IRMM-414-4/IRMM-414-5)

This report describes the preparation and certification of dry-mixed maize powder with different mass fractions of genetically modified GA21 RoundupReady® maize powder (Certified reference materials IRMM-414-0, IRMM-414-1, IRMM-414-2, IRMM-414-3, IRMM-414-4 and IRMM-414-5). The CRMs were produced in 2003 by the European Commission Directorate-General Joint Research Centre, the Institute for Reference Materials and Measurements (IRMM) in Geel, Belgiurn. The CRMs are intended for the quality control and calibration of methods for the detection of genetically modifled food. The GA21 concentration of IRMM-414 was verified with the help of DNA-based detection methods. The CRMs are available in the form of glass bottles containing 1 g of maize powder packed under argon atmosphere. Seeds of non-modified maize (seed variety 'RX670') and GA21 maize (event RX740RR) both produced by Monsanto (St. Louis, MO, USA) were rinsed with demineralised water, additionally drained and dried at 30°C in order to minimise dust contamination from other crops. The materials were prepared by quantitative turbula and dry-mixing of non-modified maize powder and GA21 maize powder. lt is recommended to use samplings not smaller than 100 mg.