Authors: V I Dvorkin
Publish Date: 2004/04/30
Volume: 9, Issue: 7, Pages: 421-424
Abstract
The adequacy of specimens to each other and of reference material to routine specimens is an important idea in the metrology of chemical analysis However the literature gives no strict definition for this notion In this paper a determination of adequacy based on the measure of adequacy is proposed For the case of two specimens the measure of adequacy is the absolute value of the difference between the systematic errors in the results from analysis of the specimens it depends on the differences in the composition and properties of the specimens The measure of adequacy of a certified reference material to a population of routine specimens is the maximum distance between the systematic error of the reference material and one of the quantiles of the systematic error distribution of the routine specimens Q0025 Q0975 the errors in this case are due to the composition and the properties of the routine specimens and other complicated measurements When the measure of adequacy can be neglected compared to the permissible error of the analysis the specimens are considered adequate Using the determination of total cholesterol in the blood serum of human beings as an example it was shown that the certified reference material used in the analysis of specimens of complex composition is often inadequate when compared to routine specimens
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