Selecting temperature-dependent variables in near-infrared spectra for aquaphotomics
Selecting temperature-dependent variables in near-infrared spectra for aquaphotomics
复制标题
在水光组学的近红外光谱中选择与温度相关的变量
DOI：
10.1016/j.chemolab.2018.10.006
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发表时间：
2018-12-15
影响因子：
3.9
通讯作者：
Shao, Xueguang
中科院分区：
文献类型：
--
作者：
Cui, Xiaoyu;Zhang, Jin;Shao, Xueguang
变温近红外光谱技术是近年来发展起来的一种分析水溶液结构的新技术。然而，由于重叠，很难从光谱中获得信息来理解温度依赖性。在这项工作中，提出了一种方法来选择的温度依赖性变量（波数）从近红外光谱在不同温度下测量。采用连续小波变换（CWT）将光谱分解为不同频率的光谱分量，然后采用蒙特-卡罗无信息变量剔除法（MC-UVE）分析变量与温度的相关性。通过模拟数据集验证了该方法的可行性，并通过水和水溶液的变温近红外光谱验证了该方法的适用性。从水的光谱中选择了几个变量，表明了水结构的复杂性。对于不同的溶液，这些变量位于相似但不完全相同的波数处，并且它们与溶质的浓度有很好的相关性，说明水的光谱可以作为反映水溶液差异的一面镜子。该方法可以提供一个工具，以确定在近红外光谱的特征变量，了解水在水系统中的功能。
Temperature-dependent near-infrared (NIR) spectroscopy has been developed and taken as a new technique for aquaphotomic studies to analyze water structures in aqueous systems. However, due to the overlapping, it is difficult to obtain the information from the spectra to understand the temperature dependency. In this work, a method was proposed for selection of the temperature-dependent variables (wavenumbers) from the NIR spectra measured at different temperature. Continuous wavelet transform (CWT) was used to decompose the spectra into the spectral components with different frequencies, and then Monte-Carlo uninformative variable elimination (MC-UVE) was employed to evaluate the dependency of the variables with temperature. The feasibility of the method was tested by simulated datasets and the applicability was proved by the temperature-dependent NIR spectra of water and aqueous solutions. Several variables were selected from the spectra of water, indicating the complexity of water structure. The variables are located at similar but not identical wavenumbers for different solutions and they have a good relationship with the concentration of the solute, demonstrating that water spectrum can be a mirror to reflect the difference of the aqueous solutions. The method may provide a tool to identify the characteristic variables in NIR spectra for understanding the function of water in aqueous systems.