EDIBLE FATS AND OILS REFERENCE MATERIALS FOR STEROLS ANALYSIS WITH PARTICULAR ATTENTION TO CHOLESTEROL .1. INVESTIGATION OF SOME ANALYTICAL ASPECTS BY EXPERIENCED LABORATORIES

The work reported here is integrated into a programme organized by the Community Bureau of Reference with the aim of developing edible oil reference materials (RMs) certified for cholesterol content. One vegetable oil (RM 162, a blend of soya and maize oils) and two animal fats (RM 163, a blend of pig and beef fats, and RM 164, an anhydrous milk fat) possessing, respectively, low, medium and high cholesterol contents were chosen for this purpose. The present paper summarizes the analytical conclusions resulting from three interlaboratory trials carried out to identify and correct for the major sources of random and systematic errors linked to the protocol and to the gas-liquid chromatographic analysis. Several improvements to the methodology, and recommendations, have been proposed for the determination of individual sterols within the certification exercise. The latter will be reported elsewhere.