基于表面增强拉曼光谱技术对三聚氰胺和硫氰酸钠的检测.pdf

工学硕士学位论文
基于表面増强拉曼光谱技术对三聚氰胺和硫
氰酸钠的检测研究
RESEARCH ON DETECTION OF MELAMINE
AND SODMUMTHIOCYANATE USING SURFACE
ENHANCED RAMAN SPECTTROSCOPY
周宇
哈尔滨工业大学
2012年7月
国内图书分类号:O443.4
学校代码:10213
国际图书分类号:53.37
密级:公开
工学硕士学位论文
基于表面增强拉曼光谱技术对三聚氰胺和硫
氰酸钠的检测研究
硕士研究生:周宇
导
师:吕志伟教授
申请学位:⊥学硕上
学科、专业:物理电子学
所在单位:光电子信息科学与技术系
答辨日期:2012年7月
授予学位单位:哈尔浜工业大学
Classified Index: 04434
U.D.C:53.37
Dissertation for the Master Degree in Engineering
RESEARCH ON DETECTION O
MELAMINE AND SODIUMI
THOCYANATE USING SURFACE
ENHANCED RAMAN SPECTROSCOPY
Candidate
Zhou Yu
Supervisor:
Prof. Lu Zhiwei
Academic Degree Applied for
Master of Engineering
Speciality:
Physical-electronics
Dept of Optic-electronics
Affiliation
Information Science and
Technology
Idate of Defence
July, 2012
Degree-conferring-institution
Harbin Institute of Technology
哈尔滨工业大学工学硕士学位论文
摘要
表面増强拉曼光谱技术(SERS)具有检测方便快捷,样品制备简单,对光
源要求低等特点,使其成为食品检测领域的重要予段之一。随着社会的发展,人
们对食品安全方面重视程度日益提高,但受于技术上:的限制,某些食品添加剂仍
只能通过传统化学检测方法进行实验室检测,檢测成本高,检测周期长成为了限
制其发展得主要原因。尤其在口常消费的乳制品行业中,非法添加剂的检测已成
为迫切研究的词题。
本论文提出通过对三聚氰胺和硫氰酸钠的拉曼光谱检测,分析两种物质的不
同分子结构引起的拉曼频移,三聚氰胺由于环面内变形振动利环呼吸振动引起在
676.8cm和984.6cm'的特征峰;硫氰酸钠由C一S伸缩振动和C=N的伸缩振动
引起在7569cm的峰和2069cm'的特征峰。
为了提高拉曼信号信噪比,论文中使用表面増强拉曼光谱技术,首先对表面
增强剂和聚氰胺水溶液和氰酸钠水溶液的不同混合比例进行了实验,首次通
过计算建立了溶胶和溶液泥合比例和特征峰强度的曲线,根掂曲线获得了最佳況
合比范围
其次,对三聚氰胺水溶液、硫氰酸钠水溶液,三聚氰胺牛奶溶液以及硫氰酸
钠牛奶溶液进行了光谱特性的分析。分析结果表明増强试剂、去离子水、牛奶等
物质对三聚氰胺和硫氰酸钠的定性分析没有影响,但是由于牛奶中大分子成分的
影响导致光谱图中信噪比有所降低。
最后,使用两种定量检测方法对三聚氰胺水溶液和牛奶溶液进行定量检测,
并对两种方法得到的数据进行数据拟合。结果表明两种方法得到的检测结果相关
性较高,对于光谱中没有内标峰的情況采用归一?化法进行定量分析;当存在内
峰时使用内标法进行定量分析。并使用得到的标准曲线计算得到理论檢测极限,
三聚氰胺水溶液和三聚氰胶牛奶溶液分別为0.4lpm和1.64pmn
关键词:表面增强拉曼光谱技术;三聚胺;硫氰酸钠;表面增强剂最佳混合
比:定量分析:
哈尔滨工业大学工学硕士学位论文
Abstract
With the social and economic development, the public is more and more
concerned with the safety of food. Especially in the matter of milk market, illegal food
additives have created a great problem which needs to be settled down immediately
However, some kinds of food additives can only be analyzed by traditional chemical
technique. The traditional technique has the defection of high cost and long detection
period which limited its further development. In the contrast, Surface enhanced
spectroscopy technology(SERS) has many advantages. It's easy and quick to operate
and make samples and it has a low requirement of laser light. For above reasons, SERS
has the potential to become an advanced method in the area of food inspection
By the detection of melamine and sodium thiocyanate in Raman spectrum, We
analyzed the Raman shift caused by different molecular structures of the two matters in
the article. With the characteristic peak of melamine is confirmed on 6768cm and
984.6cm because of deformation vibration outside in plane of ring and the rin
eathing mode
In order to improve the SNR of Raman spectrum, We used the technique of
Surface enhanced spectroscopy. First is to experiment the different blending ratios of
Sers-active substrates and Melamine solution and sodium thiocyanate solution
Second, by making spectral characteristic of melamine solution, sodium
thiocyanate solution, melami