Verification of trueness and precision of the analytical method using the IAEA approach

As part of the internal quality control of the analytical method, the measurement of a Certified Reference Material (CRM) serves to investigate if the obtained measurement result is or is not significantly biased in relation with the reported reference value. For evaluating the bias, a validated trueness and precision test (the IAEA approach) can be applied.

For trueness evaluation, the results are considered "Acceptable" if:

where:

V_ref - reference value of CRM

V_lab - value obtained in laboratory

U²_ref,lab - standard combined uncertainties associated to V_ref and V_lab

For evaluation of precision, the results are considered "Acceptable" if:

where:

ALP: Acceptable Limit of Precision, set for each analyte as a function of its concentration level and ease of determination.

A result must obtain an "Acceptable" score in both criteria to be assigned the final score of "Acceptable".

See an excel example here.