Contribution of multiway calibration to White Analytical Chemistry

In this article, the compatibility between second- and third-order calibration and White Analytical Chemistry (WAC) is exposed and discussed. The WAC concept and the principles on which it is based are briefly presented. Multiway calibration methods, which consist of performing analyte(s) quantification by processing second- or higher-order instrumental data using chemometric models, are analyzed in light of their contribution to the whiteness of an analytical method. Special emphasis is directed towards the chemometric property called "second-order advantage," which offers the possibility of modeling sample interferences without either needing to remove them nor knowing their identity. With the purpose of illustrating to the analytical community the valuable contribution of multiway calibration to the development of white methodologies, some examples selected from our laboratory are here presented.