Infrared spectroscopy of quasi-ideal binary liquid mixtures: The challenges of conventional chemometric regression

Mayerhoefer TG, Ilchenko O, Kutsyk A, Popp J (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Spectrochimica Acta Part A-Molecular and Biomolecular Spectroscopy Elsevier

Book Volume: 280

Article Number: 121518

DOI: 10.1016/j.saa.2022.121518

Abstract

We have recorded ATR-IR spectra of binary mixtures in the (quasi-)ideal systems Benzene-Toluene, Benzene-Carbon tetrachloride and Benzene-Cyclohexane and performed classical least squares, inverse least squares and principal component regression on the resulting spectra. In contrast to the general expectation, the spectra of ideal mixtures follow only roughly Beer's approximation, in particular stronger bands show shifts and increased intensities for intermediary compositions since the polarization of matter by light cannot be neglected. As a consequence, these conventional regression techniques lead to principle and unavoidable errors, even though some of the classical regression techniques are assumed to be able to cope with nonlinearities. In particular in the system Benzene-Carbon tetrachloride large errors result and the relative average error of the volume fraction determination is about 10 % for all three methods. Especially remarkable is that the multivariate regression methods do not perform better than the classical univariate calibration if for the latter a peak due to an oscillator with comparably low oscillator strength is selected, since for such bands polarization effects are weak and Beer's approximation holds comparably well.

Involved external institutions

Leibniz-Institut für Photonische Technologien e.V. DE Germany (DE) Technical University of Denmark / Danmarks Tekniske Universitet (DTU) DK Denmark (DK) Taras Shevchenko National University of Kyiv (KNU) / Київський національний університет імені Тараса Шевченка UA Ukraine (UA)

How to cite

APA:

Mayerhoefer, T.G., Ilchenko, O., Kutsyk, A., & Popp, J. (2022). Infrared spectroscopy of quasi-ideal binary liquid mixtures: The challenges of conventional chemometric regression. Spectrochimica Acta Part A-Molecular and Biomolecular Spectroscopy, 280. https://dx.doi.org/10.1016/j.saa.2022.121518

MLA:

Mayerhoefer, Thomas G., et al. "Infrared spectroscopy of quasi-ideal binary liquid mixtures: The challenges of conventional chemometric regression." Spectrochimica Acta Part A-Molecular and Biomolecular Spectroscopy 280 (2022).

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