Statistical procedure to test identity between analytical methods

The comparisons between analytical methods have been totally or partially empiric, lacking more appropriate statistical treatment. The objective of this work was to propose a statistical procedure to test the identity between analytical methods. The proposed procedure results from the combination of the F test modified from Graybill in 1976, t-test for the medium error and analysis of the linear correlation coefficient. This procedure was applied to test the identity between analytical methods in fifteen cases of comparison of an alternative analytical method in relation to standard analytical method. The results showed that the proposed statistical procedure is efficient and not subjective, and it could also be used to test the identity between any two vectors or groups of quantitative data.