ABSTRACT
Three-way calibrations methods, such as the generalized rank annihilation method (GRAM) and parallel factor analysis (PARAFAC), are becoming increasingly prevalent tools to solve analytical challenges. The main advantage of three-way calibration is estimation of analyte concentrations in the presence of unknown, uncalibrated
spectral interferents. These methods also permit the extraction of analyte, and often interferent, spectral profiles from complex and uncharacterized mixtures. In this chapter, a theoretical and practical progression and overview of three-way calibration methods from the simplest rank annihilation factor analysis (RAFA) to the more flexible PARAFAC is presented. Extensions of many three-way methods are covered to highlight the paradigm’s flexibility in solving particular analytical calibration problems.
