Handling of uncertainty due to interference fringe in FT-NIR transmittance spectroscopy - Performance comparison of interference elimination techniques using glucose-water system

Anel Beganović; Krzysztof B Beć; Raphael Henn; Christian W Huck

doi:10.1016/j.saa.2018.01.069

Handling of uncertainty due to interference fringe in FT-NIR transmittance spectroscopy - Performance comparison of interference elimination techniques using glucose-water system

Spectrochim Acta A Mol Biomol Spectrosc. 2018 May 15:197:208-215. doi: 10.1016/j.saa.2018.01.069. Epub 2018 Jan 31.

Authors

Anel Beganović¹, Krzysztof B Beć², Raphael Henn¹, Christian W Huck³

Affiliations

¹ Institute of Analytical Chemistry and Radiochemistry, CCB - Center for Chemistry and Biomedicine, Innrain 80/82, Innsbruck 6020, Austria.
² Institute of Analytical Chemistry and Radiochemistry, CCB - Center for Chemistry and Biomedicine, Innrain 80/82, Innsbruck 6020, Austria; Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan.
³ Institute of Analytical Chemistry and Radiochemistry, CCB - Center for Chemistry and Biomedicine, Innrain 80/82, Innsbruck 6020, Austria. Electronic address: christian.w.huck@uibk.ac.at.

PMID: 29433857
DOI: 10.1016/j.saa.2018.01.069

Abstract

The applicability of two elimination techniques for interferences occurring in measurements with cells of short pathlength using Fourier transform near-infrared (FT-NIR) spectroscopy was evaluated. Due to the growing interest in the field of vibrational spectroscopy in aqueous biological fluids (e.g. glucose in blood), aqueous solutions of d-(+)-glucose were prepared and split into a calibration set and an independent validation set. All samples were measured with two FT-NIR spectrometers at various spectral resolutions. Moving average smoothing (MAS) and fast Fourier transform filter (FFT filter) were applied to the interference affected FT-NIR spectra in order to eliminate the interference pattern. After data pre-treatment, partial least squares regression (PLSR) models using different NIR regions were constructed using untreated (interference affected) spectra and spectra treated with MAS and FFT filter. The prediction of the independent validation set revealed information about the performance of the utilized interference elimination techniques, as well as the different NIR regions. The results showed that the combination band of water at approx. 5200 cm^-1 is of great importance since its performance was superior to the one of the so-called first overtone of water at approx. 6800 cm^-1. Furthermore, this work demonstrated that MAS and FFT filter are fast and easy-to-use techniques for the elimination of interference fringes in FT-NIR transmittance spectroscopy.

Keywords: FT-NIR spectroscopy; Glucose; Interference fringe; PLSR; Water.