近红外光谱组合区间偏最小二乘法定量白酒中的乙酸乙酯  

Determination of ethyl acetate in liquor based on combination of near-infrared spectroscopy interval partial least squares

作　　者：谭超[1,2] 吴同[1] 李惟一[1] 张开仕[1] 覃鑫 

机构地区：[1]宜宾学院化学与化工学院,四川宜宾644007 [2]计算物理四川省高校重点实验室,四川宜宾644007 [3]川渝中烟公司,四川成都610017

出　　处：《计算机与应用化学》2014年第4期510-512,共3页Computers and Applied Chemistry

基　　金：宜宾市科技创新专项(2013GY018);四川省教育厅重点项目(12ZA201);四川省应用基础研究计划项目(2013JY0101)

摘　　要：白酒特征香味主要体现在酯类的分布和数量上,如乙酸乙酯既是清香型白酒的特征香味成分,又在浓香型、酱香型等白酒中有较高的含量,是形成白酒香味的重要物质。探讨白酒中以乙酸乙酯为代表的酪类物质检测具有重要的实际意义。传统的色谱法存在着操作复杂、耗时长等缺陷。近红外光谱以其简便、快捷、低成本、多组分同时测定以及不破坏样品等优点,在食品、化工、制药等领域得到了成功应用,与化学计量学结合被称为万能分析技术。本文通过组合近红外光谱与区间偏最小二乘算法,筛选出定量白酒中乙酸乙酯含量的最优波长区间,将变量从1175压缩到156,压缩率达87%,大大降低了计算的时间和空间复杂度。在此基础上建立了比基于全谱的偏最小二乘算法方法更简单、更精确的预测模型,显示出强的推广能力,并在独立的测试集上得到了验证。尽管只针对乙酸乙酯含量进行了实验,但实验结果具有普遍意义。Characteristic aroma of liquor is mainly reflected in the distribution and abundance of esters such as ethyl acetate. Ethyl acetate is not only the characteristically flavor components of Fen liquor, but also serves as important flavor component in Luzhou-flavor and Maotai liquors with relatively higher concentration. The method of determining esters including ethyl acetate has important practical significance. Chromatography exhibits some disadvantages because it often involves in complex operation and is very time-consuming. Nowadays, near-infrared （NIR） spectroscopy has become an effective alternative to wet chemical methods in various fields such as food and pharmaceutical industry because it is simple, rapid, non-destructive, and capable of simultaneously analyzing several constituents, and it requires little or no sample preparation. Near-infrared （N/R） spectroscopy combined with chemometrics proves to be a universal analytical technique. Based on the combination of near-infrared spectroscopy and interval partial least square, this work focuses on finding the optimal wavelength range of quantitative ethyl acetate of liquor and constructing the calibration model. The number of variables is compressed from 1175 to 156, i.e., a compression ratio of about 87 %, therefore greatly reducing the computational time and space complexity. The final model of partial least squares containing 11 components outperform the model from full-spectrum partial least squares. It also shows good generalization ability. This result has been validated on the independent test set with the same size as the training set. Even if this result only comes from the experiment associated to ethyl acetate, it has universal significance.

关 键 词：近红外光谱 区间偏最小二乘 白酒 乙酸乙酯 

分 类 号：O657.33[理学—分析化学] TS261[理学—化学]