A novel approach to constructing high-dimensional asynchronous spectra (nD-Asyn) is
proposed. Three theorems relevant to 1D slices of nD-Asyn are revealed. nD-Asyn is
used to analyze bilinear data from mixtures containing multiple components obtained
via hyphenated techniques. The spectral contribution of different components can be
removed in a stepwise manner by increasing the dimensions of asynchronous spectra.
As a result, the spectra of different components can be faithfully recovered even
if the time-related profiles of different components severely overlap. Moreover, correct
results can still be obtained via the nD-Asyn even if a considerable level of noise
and baseline drift are present. The nD-Asyn approach is compared with MCR-ALS using
different constraints in analyzing the data for a simulated and also for a real system.
The nD-Asyn produced correct spectrum of every component. Only when complete constraints
obtained from nD-Asyn method is utilized in the MCR-ALS calculation, correct spectra
of all the components can be obtained. Thus, nD-Asyn can be used alone or in conjunction
with MCR-ALS to analyze bilinear data containing contributions of multiple components.
(C) 2019 Published by Elsevier B.V.