Detection of Hydrate Forms of Lithium and Sodium Perchlorates in Aqueous Solutions Using near Infrared Spectroscopy

2014 ◽  
Vol 22 (2) ◽  
pp. 121-128 ◽  
Author(s):  
Anna G. Davidian ◽  
Andrei G. Kudrev ◽  
Lyubov A. Myund ◽  
Maria K. Khripun
NIR news ◽  
2019 ◽  
Vol 30 (5-6) ◽  
pp. 15-17
Author(s):  
Mian Wang ◽  
Xiaoyu Cui ◽  
Wensheng Cai ◽  
Xueguang Shao

Temperature-dependent near-infrared spectroscopy has been developed for studying quantitative and structural analysis, as well as the molecular interactions. Taking the advantage of the temperature effect on hydrogen bonding, the technique has shown its potential in analyzing the interactions in aqueous solutions. In our recent studies, the structural changes in homo-oligopeptides K5 (penta-lysine), D5 (penta-aspartic acid), and protein (ovalbumin) aqueous solutions were studied by temperature-dependent near-infrared spectroscopy. The thermodynamics and their interaction with water were analyzed with the help of the chemometric methods including continuous wavelet transform, independent component analysis, two-dimensional (2D) correlation analysis, and Gaussian fitting. The results show that the oligopeptide in aqueous solution improves the thermal stability of the water species, and K5 has stronger interaction with water than D5. In the gelation of ovalbumin, the change of the water species with two hydrogen bonds (S2) follows the same phases as the protein. S2 maintains the stability of the protein in native and molten globule states, and the weakening of the hydrogen bond in S2 by high temperature results in the destruction of the hydration shell and makes the ovalbumin clusters form a gel structure.


2008 ◽  
Vol 47 (13) ◽  
pp. 2227 ◽  
Author(s):  
Naoto Kakuta ◽  
Hidenobu Arimoto ◽  
Hideyuki Momoki ◽  
Fuguo Li ◽  
Yukio Yamada

1998 ◽  
Vol 102 (34) ◽  
pp. 6655-6662 ◽  
Author(s):  
Yan Wang ◽  
Koichi Murayama ◽  
Yoshiki Myojo ◽  
Roumiana Tsenkova ◽  
Nobuyuki Hayashi ◽  
...  

2021 ◽  
Vol 11 (20) ◽  
pp. 9662
Author(s):  
Miia O. Hurskainen ◽  
Jaakko K. Sarin ◽  
Sami Myllymaa ◽  
Wilfredo A. González-Arriagada ◽  
Arja Kullaa ◽  
...  

Near-infrared spectroscopy (NIRS) is a non-ionizing optical technique that can be used to quantify proteins, carbohydrates, fats, and other organic and biological substances. The aim of this study was to determine the ability of NIRS to identify different concentrations of L-fucose and L-proline solutions by utilizing different NIR spectral regions. NIR spectra of solid L-fucose and L-proline, their aqueous solutions in different concentrations, and the spectra of saliva samples collected from two patients with oral squamous cell carcinoma (OSCC) were studied. Differences in spectra of the pure solid reference samples and water were most noticeable in spectral regions 800–1250 nm and 1418–1867 nm. The saliva sample with an atypically high concentration of oral cancer biomarkers showed a similar spectral feature between 1530–1650 nm as the liquid samples with cancer biomarkers. In addition, a fine k-nearest neighbors (kNN) classifier was trained to differentiate the aqueous solutions and achieved 75.97% validation accuracy. The preliminary study presents that NIRS can be utilized to detect differences in spectra between the different biomarker concentrations in aqueous solutions. However, the qualitative measures may have resulted in limited sensitivity, which could be enhanced by additional samples and using a measurement probe dedicated to fluid measurements.


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