氯化钠对葡萄糖水溶液近红外光谱的影响

人体内钠盐的含量影响血糖代谢且与糖尿病具有较高的相关性。因此，在进行血糖的近红外光谱无创检测时，不仅要考虑血液中大颗粒及大分子物质对光谱的吸收和散射影响，也应从分子结构层面上分析小分子物质对葡萄糖分子结构及其特征吸收的影响。基于声光可调谐滤波器(AOTF)的高精度近红外光谱采集系统，测量并研究了在水溶液环境下氯化钠(NaCl)对葡萄糖分子结构及其近红外特征吸收的影响。首先，测量含有不同NaCl含量的葡萄糖水溶液透射光谱，分别采用纯水和同浓度 NaCl 样本进行背景修正，实验表明，在水溶液环境中 NaCl会改变水分子和葡萄糖分子特征吸收峰的位置和强度;对不含NaCl和含有NaCl的糖水样本分别扣除纯水和同浓度NaCl样本后进行二维相关光谱分析，同步谱的切线谱显示NaCl减弱了葡萄糖分子在1 400和1 520～1 700 nm处的特征吸收。最后，通过偏最小二乘回归模型定量分析NaCl对葡萄糖预测精度的影响，发现模型的预测均方根误差随NaCl含量的增加而增大，并且含NaCl的样本与不含NaCl的样本对葡萄糖浓度预测值之差的平均值与加入的NaCl含量近似为线性关系。结果表明，在水溶液环境下NaCl分子会改变葡萄糖分子键状态并影响其特征吸收，从而降低模型的预测精度。若将NaCl含量作为变量因子，有助于提升血糖的近红外光谱无创检测精度。

Study on the Effect of Sodium Chloride Salt on Near-Infrared Spectroscopy of Glucose Aqueous Solution

that NaCl also affect the combination of glucose and water molecules .And the two‐dimensional correlation spectroscopy analysis is performed under the perturbation of glucose concentration .The slice spectra of synchronous correlation spectra show that ,the adding of NaCl weakens the spectral variation due to glucose concentration change in the wavelength of 1 400 and 1 520 ~ 1 700 nm .Finally ,the partial least square (PLS) regression models were built to quantitatively conduct the influence of NaCl on glu ‐cose prediction accuracy .Comparison results showed that ,NaCl molecule in aqueous solution will deteriorate the model accura‐cy ,where root mean square error of prediction increases with the NaCl content ;the mean difference of predicted glucose concen‐tration between models based on glucose aqueous solutions with NaCl and without NaCl ,is linear with NaCl concentration in samples .