<Emphasis Type="Italic">A priori</Emphasis> evaluation of the adequacy of reference materials

The concept of adequacy of reference materials (RMs) to samples under analysis is discussed. It is emphasized that effectiveness of RM as a measurement standard can depend dramatically on assessment of the RM adequacy. A score is proposed for quantitative adequacy evaluation that formalizes the existing analytical knowledge. The score is based on the comparison of the compositions and physico-chemical parameters of RM with those of a sample, choosing the parameters influencing the analytical results. The score allows us to find the most adequate RM before analysis, using RM catalogues and prior information about the sample and analytical method.