The certification of reference materials of dry-mixed maize powder with different mass fractions of Bt-11 maize : certified reference materials ERM-BF412a, -BF412b, -BF412c, -BF412d, -BF412e, -BF412f

This report describes the preparation and certification of dry-mixed maize powder CRMs with different mass fractions of genetically modified Bt-11 maize powder (Certified Reference Materials IRMM-412R-0, IRMM-412R-1, IRMM-412R-2, IRMM-412R-3, IRMM-412R-4 and IRMM-412R-5). The CRMs were produced in 2002 by the Joint Research Centre of the European Commission, the Institute for Reference Materials and Measurements (IRMM) in Geel, Belgium. The CRMs are intended for the calibration of methods for the detection of genetically modified food. The Bt-11 concentration of IRMM- 412R 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 'Pelican') and Bt-11 maize (event NX 3707 Bt11) both produced by Syngenta Seeds S.A.S. (Nérac, FR) 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 Bt-11 maize powder. It is recommended to use samplings not smaller than 100 mg.