Development of low and elevated level multivitamin and mineral supplement certified reference materials: VITA-1 and VITB-1

VITA-1 and VITB-1 are low- and elevated level CRMs, respectively, which were certified for minerals and vitamin contents by National Research Council Canada. The proportions of key ingredients are the same in each formula, and they were prepared in such a way that VITB-1 has twice the amount of minerals and vitamins as VITA-1. The availability of these two matrix-matched CRMs, with different concentrations for all analytes, will not only assist in the validation of procedures and the development of methods for the determination of respective analytes in multivitamins or samples of a similar matrices, but also will be useful for calibration purposes (for the values that are certified). Tablets were individually packaged in trilaminate foil pouches and values presented in the certificate of analysis are expressed on a “as is” basis, with no need for the determination of moisture content on a separate test portion. In addition, certified/reference values are provided per single tablet (mass fraction expressed as both mg/kg and µg/tablet), eliminating the need of a homogenization step prior to analysis. Homogeneity and stability were assessed and included in the final expanded uncertainties of the certified values. Quantity value assignment for both VITA-1 and VITB-1 was based on the use of at least two independent methods, using data generated at NRC and data from external collaborators for confirmation purposes. As a result of this campaign, value assignment was possible for a total of 39 analytes: 24 trace elements and 15 vitamins.