THE CERTIFIED TOTAL GLUCOSINOLATE CONTENT IN 3 RAPESEEDS (CRM-190, CRM-366 AND CRM-367)

The preparation of certified rapeseed reference materials and the step s taken to establish the certified values for total glucosinolate cont ents are described. Details are given of the studies to demonstrate th e homogeneity and stability of the material. The results of the certif ication exercise for total glucosinolate content, which involved Europ ean laboratories who applied a variety of methods (high-pressure liqui d chromatography, gas liquid chromatography, determination of enzymati cally released glucose and sulphate), are presented and discussed. The certified values for the glucosinolate content (mumol/g of non-defatt ed whole seeds) and the 95% confidence level are the following: CRM 36 6 (12.1 +/- 0.8 mumol/g), CRM 190 (25.5 +/- 0.9 mumol/g) and CRM 367 ( 102.4 +/- 3 mumol/g) (CRM = certified reference material). Indicative values (not certified) for individual glucosinolates are also given. C ertified sulphur values (mg/g of non defatted whole seeds) have been d etermined by other laboratories: CRM 366 (3.41 +/- 0.12 mg/g), CRM 190 (4.93 +/- 0.15 mg/g) and CRM 367 (10.5 +/- 0.40 mg/g).