Terahertz signatures and quantitative analysis of glucose anhydrate and monohydrate mixture

Hui Yan; Wenhui Fan; Xu Chen; Lutao Liu; Hanqi Wang; Xiaoqiang Jiang

doi:10.1016/j.saa.2021.119825

Terahertz signatures and quantitative analysis of glucose anhydrate and monohydrate mixture

Spectrochim Acta A Mol Biomol Spectrosc. 2021 Sep 5:258:119825. doi: 10.1016/j.saa.2021.119825. Epub 2021 Apr 20.

Authors

Hui Yan¹, Wenhui Fan², Xu Chen³, Lutao Liu⁴, Hanqi Wang⁴, Xiaoqiang Jiang⁴

Affiliations

¹ State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China; College of Science, Zhongyuan University of Technology, Zhengzhou 450007, China; Zhengzhou Key Laboratory of Low-dimensional Quantum Materials and Devices; University of Chinese Academy of Sciences, Beijing 100049, China.
² State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China; University of Chinese Academy of Sciences, Beijing 100049, China; Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China. Electronic address: fanwh@opt.ac.cn.
³ State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China.
⁴ State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China; University of Chinese Academy of Sciences, Beijing 100049, China.

PMID: 33901947
DOI: 10.1016/j.saa.2021.119825

Abstract

Glucose, as the main energy carrier and significant source of nutrition, generally comes in two available forms of anhydrate and monohydrate in commercial production. Considering their respective application occasions, proper identification of glucose in single composition or binary-mixture and quantification of the mixture are crucial in industry monitoring to guarantee merchandise quality. Simultaneously, public confusions of glucose are rather ubiquitous partly due to anhydrate and monohydrate with identical white crystalline appearance. In this paper, utilizing the molecular fingerprints of terahertz (THz) technology that are corresponding to structural characteristics of anhydrous and hydrated form, THz signatures of glucose anhydrate, monohydrate and their mixture, as well as THz spectral transformation from monohydrate to anhydrate with the dehydrating process are systematically studied. Some visible peaks of monohydrate were noted at 1.82 and 1.99 THz signifying the presence of hydrated structure. However, with the dehydrating process, the peaks related to the hydrated structure are not very apparent when the peaks at 1.44 and 2.08 THz appear due to changes in the molecular structure of anhydrate, which provide clear indication for hydrogen-bond network reconstruction at the micro level. Furthermore, characteristic peaks at 1.44 and 1.82 THz can be specified as the main quantitative indicators for quantitative detection. The linear relationships between the amplitudes of characteristic peaks and the percentage compositions of anhydrate and monohydrate are revealed. Three commercially available brands of edible glucose powder A, B, C were effectively identified by THz signatures. While powder C was recognized as binary-mixture and the proportion of anhydrate and monohydrate was further quantified. THz spectroscopy technology has advantages of direct recognition, simple quantitative model based on THz absorption peaks, and no need for complicated chemical treatment. It may be potentially shed light on industrial monitoring of glucose production and other related mixture in the future.

Keywords: Anhydrate and monohydrate; Glucose; Mixture; Quantitative analysis; THz signature.

MeSH terms

Glucose*
Hydrogen Bonding
Molecular Structure
Powders
Terahertz Spectroscopy*

Substances

Powders
Glucose