基于表面增强拉曼光谱快速定量检测碳酸饮料中苯甲酸钠的方法

Rapid and Quantitative Detection Method of Sodium Benzoate in Carbonated Beverage Based on Surface-Enhanced Raman Spectroscopy

利用实验室自行搭建的拉曼光谱检测系统,确定了苯甲酸钠位于843.5cm-1、1007cm-1和1605cm-1处的3个拉曼特征峰;以柠檬酸钠还原硝酸银配制的银溶胶作为表面增强剂,设计了快速检测市售碳酸饮料中苯甲酸钠含量的方法。将44个苯甲酸钠浓度不同的碳酸饮料的原始光谱曲线进行Savitzky-Golay平滑降噪及基线背景扣除预处理,然后随机分为32个校正集和12个验证集,采用一元线性回归、多元线性回归、偏最小二乘回归、主成分回归和支持向量机回归等方法进行建模。结果表明,以843.5cm-1、1605cm-1处的2个特征峰建立的二元线性回归模型的建模结果最好,验证集相关系数为0.9603,验证集的均方根误差为0.0867×10-3。该二元线性回归模型可以实现市售碳酸饮料中苯甲酸钠的快速定量检测,为食品中的苯甲酸钠含量的实时在线检测提供了技术支撑。

Three Raman characteristic peaks of sodium benzoate located in 843.5 cm-1 , 1007 cm-1 and 1605 cm-1 are identified by using self-built Raman spectroscopy detection system. Using silver colloidal prepared by reduction of silver nitrate with sodium citrate as surface enhancer, we develop a rapid detection method for sodium benzoate in commercial carbonated beverage. The surface enhanced Raman spectra of 44 carbonated beverage samples with different sodium benzoate concentrations are randomly divided into 32 calibration sets and 12 validation sets, and all Raman spectra are carried out the pretreatments of Savitzky-Golay smoothing and baseline removal of fluorescence background. Simple linear regression analysis method, multiple linear regression analysis method, partial least squares regression analysis method, principal component regression analysis method and support vector machine regression analysis method are used to build models. The results show that the optimal model is binary linear regression analysis model based on the sodium benzoate characteristic peaks at Raman shift of 843.5 cm-1 and 1605 cm-1 . In the binary linear regression model, correlation coefficient of validation set is 0. 9603, root mean square error of validation set is 0. 0867 × 10^-3. The rapid and quantitative detection of sodium benzoate in commercial carbonated beverages can be realized by the binary linear regression analysis model, and this provides technical support for the real-time online detection of the content of sodium benzoate in food.