The method-specific certification of the cholesterol and triglyceride contents of a pure and an adulterated butter fat reference material : BCR-632A and BCR-632B

This report describes the preparation of a set of two butter fat reference materials (pure and adulterated butter fat) and the measurement exercises that led to the method-specific certification of the content (relative mass fraction) of the triglycerides C24 - C54 (even numbers) and cholesterol. The content of the triglycerides and of cholesterol has been normalised to 100 g. The relative mass fractions are presented in Table 1. The results of the certification exercise, which involved 11 European laboratories, are presented and discussed. Uncertainties were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) including uncertainties due to possible inhomogeneity and possible instability as well as uncertainty contributions from the calibrant (impurities and weighing).