Analysis of three- and four-way data using multivariate curve resolution-alternating least squares with global multi-way kinetic fitting

This paper demonstrates a novel implementation of an alternating least squares (ALS) algorithm for resolving three- and four-way data. Computer-simulated multi-way data are studied as well as the multi-way data obtained from typical kinetic experiments observed using liquid chromatography with diode array detection (LC-DAD) and UV–visible spectroscopy. Each data set is analyzed using this new multi-way ALS algorithm, not only providing estimates of the spectral profiles (and retention profiles in the case of LC-DAD measurements) for each of the components involved, but also simultaneously estimating the rate constants for the reaction steps at different experimental conditions using a global kinetic analysis. However, when the reaction conditions do not require that all the rate constants are identical for each experiment, as is the case when the reactions are observed at different temperatures, the data analysis still benefits from the common information present in the data, such as spectral and retention profiles, as well as a common reaction mechanism.