IMPROVEMENTS IN THE DETERMINATION OF VITAMINS IN FOODS - METHOD INTERCOMPARISON STUDIES AND PREPARATION OF CERTIFIED REFERENCE MATERIALS (CRMS)

Accurate methods for the determination of vitamins in food are require d for nutritional labelling, and for the production of food compositio n data for nutritional research on relationships between diet and heal th. The Standards, Measurement and Testing Programme of the European C ommission is supporting a collaborative project involving 48 laborator ies to improve their measurement in food. The research programme invol ves the use of method intercomparison studies to identify and control systematic errors, optimization of sample extraction and clean-up proc edures, and the preparation of suitable food reference materials (RMs) . Results are presented for the determination of vitamin D-3 by HPLC a nd folates by microbiological assay in various foods demonstrating imp roved agreement between laboratories and possible reasons for improvem ents. In addition, examples of the food RMs produced and their potenti al use are described. Copyright (C) 1996 Elsevier Science Ltd