4材料催化发光光谱阵列传感器用于识别咖啡的研究

发布时间：2018-09-04 17:46

【摘要】：对具有非常相似组成的复杂混合物进行识别一直是分析化学界研究的热点和难点,也是对研究人员的挑战。另一方面,人们对食品的质量和安全越来越重视,对食品安全的监管不容忽视。所以,发展精确简单快捷的分析测试方法,用于食品质量的监控以及食品真伪的鉴别是十分必要的。使用化学传感器的方法已经成为分析测试技术的重要手段。其中催化发光(Cataluminescence,CTL)传感器扮演着重要的角色,CTL是利用有机物在固体催化材料表面发生催化氧化反应释放微弱的光的过程。由于不同分析物的扩散速率不同、物理或化学的吸附作用不同,而且不同结构的分析物会产生不同结构的中间体和产物,因此产生的发光信号不同。在CTL反应体系中可以同时方便地收集丰富的信息,如信号强度、反应时间、波长、光谱形状和其他的因素。CTL传感器为区分结构相似物提供了有力手段。另外,CTL传感器不需要光源,避免了散射光干扰问题,同时消除了光源不稳定的影响,具有设备简单、灵敏度高、分析速度快等优点,具有很好的应用前景。本论文的主要研究内容如下:(1)在一个反应密闭体系中,用四种纳米催化材料(nano-MgO,nano-Y2O3,nano-Eu2O3,nano-Al2O3)构建了一种新型的CTL光谱阵列传感器。该传感器和单材料CTL光谱阵列传感器具有相同大小的体积,却可以测定更加丰富的CTL信号信息。(2)以识别咖啡这种复杂混合物为目标,配置一定浓度的咖啡溶液为待测对象。每种咖啡溶液在该传感器的一种催化材料上发生CTL反应时,以不同的波长的滤波片为单色器,进行波长扫描实验,CTL反应所释放的在15个波段的光强度被分别记录下来,我们称之为单材料CTL光谱阵列;在四种传感材料上分别发生CTL反应时,可获得4组不同的光谱阵列,60个发光强度,我们称之为4材料CTL光谱阵列。(3)在数据的处理方法中,以化学计量学为主体,以统计软件SPSS 20.0为工具,用线性判别分析(LDA)和层次聚类分析(HCA)对7种速溶黑咖啡的单材料CTL光谱阵列进行分类,然后再用LDA和HCA对7种速溶黑咖啡的4材料CTL光谱阵列进行分析。结果表明,对单材料CTL光谱阵列的LDA和HCA两种分析方法均能使7种咖啡较好的分类,但以4材料CTL光谱阵列为分析对象时,分类效果更加明显。(4)用LDA和HCA方法对14种混合咖啡的单材料CTL光谱阵列进行分析,大部分咖啡被识别,但无法达到14种咖啡完全正确分类的目的。用LDA方法对2材料CTL光谱阵列、3材料CTL光谱阵列、4材料CTL光谱阵列分析,结果表明随着CTL光谱阵列的增加,不同咖啡之间的分界线越来越明显,14种咖啡被准确归类。用HCA进行同样的处理,得到了同样的结果。(5)对不同咖啡的CTL反应机理进行了初步探讨。咖啡中所含不同物质发生的CTL反应不同、所产生的光信号也不相同。CTL光谱阵列是很多种含量不同的物质在一定条件下发生CTL反应时,所产生的光总和的记录。当反应外界条件、催化材料的使用等发生变化时,均会使CTL反应的光谱阵列存在不同。进而达到识别的目的。本研究用4材料CTL光谱阵列传感器成功鉴别了成分复杂的咖啡混合物,为具有相似组分混合物的鉴别提供了新的参考方法。针对不同的混合物的性质制作多材料CTL光谱阵列传感器,可以对混合物进行很好的识别。
[Abstract]:Recognition of complex mixtures with very similar compositions is always a hot and difficult topic in analytical chemistry and a challenge to researchers. On the other hand, people pay more and more attention to the quality and safety of food, and the supervision of food safety can not be ignored. It is necessary to monitor the quality of food and identify the authenticity of food. The use of chemical sensors has become an important means of analysis and testing technology. Cataluminescence (CTL) sensors play an important role. CTL is the use of organic compounds on the surface of solid catalytic materials catalytic oxidation reaction release weak. The process of light. Different analytes have different diffusion rates, different physical or chemical adsorption, and different structures of analytes produce different structures of intermediates and products, thus producing different luminescent signals. In CTL reaction systems, abundant information such as signal intensity, reaction time, and wave can be easily collected at the same time. In addition, the CTL sensor does not need light source, avoids the problem of scattering light interference, and eliminates the influence of light source instability. It has the advantages of simple equipment, high sensitivity, fast analysis speed and so on. It has a good application prospect. The main research contents are as follows: (1) A novel CTL spectral array sensor was constructed in a closed reaction system using four kinds of nano-catalytic materials (nano-MgO, nano-Y2O3, nano-Eu2O3, nano-Al2O3). In order to identify the complex mixture of coffee, a certain concentration of coffee solution was allocated as the object to be tested. When each coffee solution reacted with CTL on one of the catalytic materials of the sensor, a wavelength scanning experiment was carried out with different wavelength filter as monochromator. The intensity of light released by the CTL reaction in 15 bands was recorded separately. When CTL reaction occurs on four kinds of sensing materials, four groups of different spectral arrays and 60 luminous intensity can be obtained, which we call the CTL spectral array of four materials. (3) In the data processing method, stoichiometry is the main body, and statistical software SPSS 20.0 is the tool, linear discrimination is used. Analysis (LDA) and Hierarchical Cluster Analysis (HCA) were used to classify the CTL spectral arrays of seven instant black coffees, and then the CTL spectral arrays of four materials of seven instant black coffees were analyzed by LDA and HCA. The results showed that both LDA and HCA could classify the seven kinds of coffees better, but the four materials were used to classify the four kinds of instant black coffees. Fourteen kinds of mixed coffee were analyzed by LDA and HCA. Most coffees were identified, but 14 kinds of coffees could not be classified correctly. Two kinds of CTL spectral arrays, three kinds of CTL spectral arrays, four kinds of CTL spectral arrays were classified by LDA. Column analysis showed that with the increase of CTL array, the boundaries between different coffees became more and more obvious, and 14 kinds of coffees were accurately classified. The same results were obtained by the same treatment with HCA. (5) The mechanism of CTL reaction of different coffees was preliminarily discussed. CTL spectroscopic array is a record of the total amount of light produced by CTL reaction under certain conditions. When the external conditions of reaction and the use of catalytic materials change, the spectral array of CTL reaction will be different. Spectral array sensors have successfully identified coffee mixtures with complex components, providing a new reference method for identifying coffee mixtures with similar components.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O657.3;TS273

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