- Title
- Quantum chemical computation-based strategy for alternating least squares initialization in multivariate curve resolution analysis of spectral-pH data
- Creator
- Brasca, Romina; Kelterer, Anne-Marie; Maeder, Marcel; Alcaráz, Mirta R.; Culzoni, Maria J.
- Relation
- Microchemical Journal Vol. 140, Issue July 2018, p. 183-188
- Publisher Link
- http://dx.doi.org/10.1016/j.microc.2018.04.022
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2018
- Description
- The main motivation of this work is to provide initial estimates for the initialization of the iterative optimization within the multivariate curve resolution - alternating least squares (MCR-ALS) algorithm for the decomposition of second-order data. It is demonstrated that the combination of quantum chemical calculations with chemometrics constitutes a novel strategy for the ALS initialization in the MCR resolution of pH-modulated chemical data. In this work, the second-order data arise from acid-base experiments of p-nitrophenol (pNP) done under a pH-gradient generated by an automated flow injection (FI) system monitored by UV-vis spectroscopy. The absorption spectra of the species involved in the chemical equilibrium were simulated by means of time-dependent density functional theory (TD-DFT) methods and were utilized to start the ALS optimization. The new approach based on the Tamm-Dancoff-approximation (TDA) CAM-B3LYP method is recommended to obtain the simulated spectra to initialize MCR-ALS, as an alternative to the routinely methods used to generate initial estimates.
- Subject
- molecular absorption spectroscopy; multivariate curve resoluton - alternating least squares; time-dependent density functional theory; initial estimates
- Identifier
- http://hdl.handle.net/1959.13/1440930
- Identifier
- uon:41265
- Identifier
- ISSN:0026-265X
- Language
- eng
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