Calibration methods for complex second-order data

In this paper, different three-way methods are tested for their power and shortcomings to solve complex second-order calibration problems. The generic calibration problem is quantifying for an analyte in the presence of an unknown interferent: a second-order calibration problem. Due to rank restrictions of the data, standard second-order calibration methods like Generalized Rank Annihilation cannot be used to solve the type of complex second-order calibration problems shown in this paper. Different real examples are tested in which it is shown that the three-way methods can, to a certain extent, deal with the complex calibrations. This stresses the fact that all second-order calibration methods should be regarded as three-way methods, and when put in this framework, can be compared with respect to their performance. (C) 1999 Elsevier Science B.V. All rights reserved.