发布时间：2014-05-09 来源：人大经济论坛

食品科学与工程论文范文 目 录 中文摘要........................................................Ⅰ 英文摘要 ......................................................II 目 录 .......................................................III 1.绪论 .........................................................1 2.多组分同时测定的原理及实验方法 ...............................3 2.1计算分光光度法测定多组分的原理 .........................3 2.2实验方法与技术...........................................3 2.2.1吸收系数矩阵ε的求解................................3 2.2.2混合标准溶液的配制 .................................4 2.2.3检测波长位置的选择..................................4 3.小波变换基本原理...............................................6 4.实验部分 .....................................................8 4.1仪器和主要试剂 .........................................8 4.2吸收曲线测定.............................................8 4.3样品稳定性试验 .........................................8 4.4训练样本吸光度测定.......................................8 4.5方法适用性试验...........................................8 4.6样品加标回收试验.........................................8 4.7未知样品吸光度测定 .....................................8 5.结果与讨论.....................................................9 5.1吸收曲线与测定波长的选择.................................9 5.2样品稳定性分析...........................................9 5.3训练样本的确定 ..........................................10 5.4主成分数的确定 ..........................................12 5.5小波系数的确定 ..........................................12 5.6方法适用性试验 ..........................................13 5.7加标回收试验 ...........................................15 5.8未知样品预报 ............................................15 6.总结与展望 ....................................................17 致谢 ........................................................18 参考文献 ........................................................19 附录A 81组分吸光度数据..........................................21 附录B MATLAB相关程序 28 摘 要：在多组分样品的分光光度法测定中，吸收曲线常会发生不同程度的重叠,采用一般分光光度法难于定量每一组分，而近年来发展起来的小波变换现已成为信息科学中的一个新兴研究领域，越来越多地应用于化学研究领域中各种复杂的、非线性的问题，也取得了很好效果。本文采用原始吸光度数据的1尺度低频系数C构造分析矩阵进行PLS回归分析，预测结果优于原始数据全谱模型。本文用小波变换-偏最小二乘回归分光光度法对对乙酰氨基酚(ACET)、愈创木酚甘油醚（GUAI）、咖啡因（CAFF）和扑尔敏（CHLO）的四组分体系进行了同时测定。加标回收率介于100.36-118.50%，结果基本满意。使用小波系数进行PLS建模，不仅可以消除原始信号中的部分噪声，而且较大地压缩了数据量，提高了预测精度。综上所述，小波变换-偏最小二乘法结合分光光度法为多组分的同时测定提供了一种新的简便、可靠的方法。 关键词：小波变换；偏最小二乘；紫外分光光度法；多组分同时测定；感冒液 Abstract: Determinate the multi-component samples, the absorption curve offen overlaps in varying degrees , It is difficult to quantitate each component using spectrophotometry generally, but the wavelet transforrrmtion (WT) in the field of chemical application which particularly in the field of nonlinear applications are very wide and have achieved good results. In this paper,Using a standard low-frequency coefficient C1 for the original absorbance data to structure analysis matrix to PLS regression analysis, forecasting results is better than the original entire spectrum model.In this paper using WT-PLS spectrophotometry to simultaneously determinate the Cough Syrup which has four components: acetaminophen, guuaifenesin, caffeine, p-aminophenol.the recovery ranged from 100.36% to 118.50% ,the result is basically satisfied. Using wavelet coefficients to build PLS model, not only can eliminate some of noise in the original signal , but also can greatly reduce the volume of data,the forecast accuracy can be improved,.In conclusion,the WT-PLS spectrophotometry provides a simple, reliable method for the simultaneous determination of multi-component. Keywords: wavelet transforrrmtion；PLS；UV spectrophotometry；simultaneous determination of multiple components；Cough Syrup