罗丹明B拉曼散射检测中光谱处理方法与实验研究

发布时间：2018-06-17 00:21

本文选题：罗丹明B + 拉曼散射　；参考：《湖北工业大学》2017年硕士论文

【摘要】：随着人民生活水平的提高,人们越来越关心食品的安全,食品安全始终是社会关注的重大问题,而食品中各种违法添加物是健康食品的重大威胁之一。拉曼散射检测技术大多不接触试样,无需对试样进行预处理,具有快速、准确的优点。本文以违法添加物罗丹明B为研究对象,运用拉曼散射检测技术实现了对罗丹明B拉曼图谱的获取和实验数据处理,论文的主要内容如下:1、基于表面加强拉曼信号技术,对罗丹明B拉曼信号加强方法进行了实验研究。对比了纳米Ag增强剂和Au增强剂对罗丹明B拉曼信号的增强效果,以及Ag增强剂中匹配剂的作用。在此基础上,探讨了Ag增强剂,罗丹明B水溶液,匹配剂添加体积比例对拉曼信号增强效果的影响。结果表明,在785nm激光激发下,Ag增强剂对罗丹明B拉曼信号增强效果更佳,匹配剂的加入可显著提高增强效果;当罗丹明B溶液浓度为0.7ppm时,当Ag增强剂:罗丹明B水溶液:匹配剂添加体积比例为1:4:1时,罗丹明B拉曼信号强度最大。2、在拉曼信号平滑去噪中,利用小波变换和窗口滑动平均法对罗丹明B拉曼信号进行了去噪,对比RSN和RMSE,小波变换硬阈值化法平滑去噪作用更好。在拉曼光谱基线消除中,在分段多项式拟合基线的基础上,创新利用了分段三次样条拟合基线的有效方法。三次样条函数其特点是一、二阶导数连续可导,则其刻画出的曲线连接过渡平滑,用其拟合光谱基线,能改善信号的信噪比。通过对比最小二乘法拟合基线方法,其拟合出的基线不仅平滑而且准确,对罗丹明B的光谱基线消除效果更好。3、利用峰面积来计算拉曼特征峰光谱强度,并基于Wasson峰面积计算公式提出了累加峰强值法快速计算拉曼特征峰强度。针对拉曼光谱定量分析方法,结合外标法研究了多变量线性回归方法,通过主成分线性回归和偏最小二乘法线性回归完成了对罗丹明B拉曼数据的简单定量分析。
[Abstract]:With the improvement of people's living standards, people are more and more concerned about the safety of food. Food safety has always been a major concern of the society, and various illegal additives in food is one of the major threats to healthy food. Most Raman scattering techniques do not contact the sample and do not need to be pretreated. It has the advantages of rapidity and accuracy. In this paper, the illegal additive Rhodamine B is used as the research object, and the Raman spectrum of Rhodamine B is obtained and the experimental data are processed by Raman scattering technique. The main contents of this paper are as follows: 1, based on surface-enhanced Raman signal technology. The enhancement method of rodamine B Raman signal was studied experimentally. The effects of nano-Ag reinforcements and au reinforcements on the Raman signal enhancement of Rhodamine B and the matching agents in Ag reinforcements were compared. On this basis, the effects of Ag reinforcer, Rhodamine B aqueous solution and the proportion of matching agent on the enhancement of Raman signal were discussed. The results show that the enhancement effect of Ag on the Raman signal of Rhodamine B is better under the excitation of 785nm laser, and the enhancement effect can be improved by adding the matching agent, and when the concentration of Rhodamine B solution is 0.7ppm, the enhancement effect is better when the concentration of Rhodamine B solution is 0.7ppm. When Ag reinforcer: Rhodamine B aqueous solution: matching agent added volume ratio is 1:4:1, the intensity of Rhodamine B Raman signal is maximum. The rodamine B Raman signal is de-noised by wavelet transform and window moving average method. Compared with RSN and RMSE, wavelet transform hard threshold method is better for smooth denoising. On the basis of piecewise polynomial fitting baselines, the effective method of piecewise cubic spline fitting baselines is innovated in the elimination of Raman spectral baselines. The cubic spline function is characterized by continuous derivation of first and second derivative, then the curve is smooth and the signal to noise ratio can be improved by fitting the spectral baseline with the cubic spline function. By comparing the least square method to fit the baseline, the fitted baseline is not only smooth and accurate, but also can eliminate the spectral baseline of Rhodamine B. the spectral intensity of Raman characteristic peak is calculated by using peak area. Based on the formula of Wasson's peak area, the accumulative peak intensity method is proposed to calculate the Raman peak intensity quickly. In this paper, the multivariate linear regression method is studied based on the quantitative analysis of Raman spectroscopy and the external standard method. The simple quantitative analysis of rhodamine B Raman data is accomplished by principal component linear regression and partial least square linear regression.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS207.3;O657.37

【参考文献】