Regression techniques for the detection of analytical bias

Abstract

Regression techniques are commonly applied to compare two analytical methods at several concentrations and to test the biases of one method relative to another. However, regression is strictly applicable only when one method is without error, for example in comparisons with reference materials. A regression-like technique, maximum-likelihood fitting of a functional relationship (MLFR), is explained and is demonstrated to work well. Under some conditions weighted regression provides a good approximation to MLFR, and so can be used if more convenient.