拉曼光谱定量分析乙醇含量的非线性回归方法研究

发布时间：2018-05-18 14:36

本文选题：激光拉曼光谱 + 乙醇浓度　；参考：《光谱学与光谱分析》2016年06期

【摘要】：传统拉曼特征峰峰比法一般采用线性回归法建立乙醇浓度与峰峰比的线性关系从而反演乙醇浓度实现乙醇定量分析,但仅在较低浓度范围适用。针对这一问题,采用自主研制的激光拉曼乙醇含量检测系统实验研究了不同浓度乙醇溶液拉曼光谱特征峰(非对称CH_2伸缩振动2 924.0cm~(-1))与本底水峰(3 350cm~(-1))相对强度关系,提出适用于大范围乙醇浓度测量的非线性回归分析方法。利用邻域平均算法去除拉曼光谱突变噪声,结合多点插值处理实现光谱基线校准。基线校准及归一化处理后,可有效消除突变噪声及强荧光背景的影响。分别采用二次多项式和e指数数学模型对拉曼峰值强度比随乙醇浓度变化关系进行非线性回归并与线性回归分析进行对比。结果表明,线性拟合相关系数约为0.991,线性回归模型乙醇浓度准确测量的适用范围为15%~60%;非线性拟合相关系数高于0.997,非线性回归模型乙醇浓度精确测量的适用范围为3%~97%。非线性数学模型可为乙醇溶液浓度定量分析提供理论基础,将该数学模型应用于乙醇含量检测系统,可实时反演较为精确的乙醇浓度,从而实现大浓度范围内具有荧光背景干扰的乙醇溶液快速、实时、准确的定量分析。
[Abstract]:The traditional Raman characteristic peak to peak ratio method generally uses linear regression method to establish the linear relationship between ethanol concentration and peak peak ratio, so as to invert ethanol concentration to achieve ethanol quantitative analysis, but only in the lower concentration range. In this problem, the independent developed laser Raman ethanol content detection system has been used to study the ethanol solubility of different concentrations. The relative intensity relationship between the characteristic peak of liquid Raman spectrum (asymmetric CH_2 telescopic vibration 2 924.0cm~ (-1)) and the base water peak (3 350cm~ (-1)) is relative, and a nonlinear regression analysis method is proposed for the measurement of the concentration of ethanol in large range. Using the neighborhood average algorithm to remove the sudden noise of the Raman spectrum and the calibration of the baseline spectrum with the multi point interpolation processing. After the quasi and normalization treatment, the effect of mutation noise and strong fluorescence background can be eliminated effectively. The nonlinear regression of the relationship between the peak intensity ratio and the concentration of ethanol with the two polynomial and e exponents is compared with the linear regression analysis. The results show that the linear regression correlation coefficient is about 0.991, and the linear regression is linear regression. The application range of accurate measurement of model ethanol concentration is 15%~60%, the correlation coefficient of nonlinear fitting is higher than 0.997. The application range of accurate measurement of ethanol concentration of nonlinear regression model is 3%~97%. nonlinear mathematical model can provide theoretical basis for the quantitative analysis of ethanol solution concentration, and the mathematical model is applied to the system of ethanol content detection. The accurate ethanol concentration can be retrieved at the time to achieve rapid, real-time and accurate quantitative analysis of ethanol solution with fluorescence background interference in a large concentration range.
【作者单位】：哈尔滨工业大学(威海)信息与光电子研究所;
【基金】：国家自然科学基金项目(41306092) 山东省自然科学基金项目(ZR2013DQ026) 山东省科技发展计划项目(2011GHY11514) 中央高校基本科研业务费专项资金项目(HIT.NSRIF.2016087)资助
【分类号】：TQ223.122;O657.37

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