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1、河北大学 硕士学位论文 ICP光源辐射强度的增强方法研究 姓名：陈凤玲 申请学位级别：硕士 专业：光学 指导教师：陈金忠 2011-05 摘 要 I 摘 要 本文采用电感耦合等离子体原子发射光谱法（Inductively Coupled Plasma Atomic Emission Spectrometry，ICP-AES）检测水溶液样品中的微量元素，主要研究了电感耦 合等离子体辐射强度的增强方法。随着科学技术的迅猛发展， ICP-AES 已被广泛应用于 不同类型物质的成分分析，同时也提出了更高的检测要求。为了适应科研与生产需要， 往往通过采取一定的措施来提高光谱仪器的分析能力，以便降低光谱分
2、析检出限，从而 得到更加精密准确的分析结果。本文采用的方法主要有以下几个方面： 1. 研究了将有机物正丙醇添加到试样中，然后检测对 ICP 发射光谱强度的影响。 结果显示，有机物的加入明显增强了试样中所测元素的谱线强度和光谱信背比，并且确 定了最佳实验条件。 2. 探讨了经过电磁场作用后，溶液样品的物理性质（表面张力和粘度） 、雾化特性 和光源辐射强度的变化。 结果发现， 在 280mT 的磁感应强度下， 对水样品溶液磁化 10min 以后，溶液的表面张力和粘度都有明显降低，雾化效率增大，使得大多数元素的发射光 谱强度有显著增强，信背比明显提高；通过测量等离子体参数，发现分析元素的激发条 件得
3、到了改善。 3. 在水溶液中加入易电离元素的添加剂氯化钾，可以提高等离子体的激发能力， 讨论了不同含量的钾元素对 ICP 光源的辐射强度和光谱信背比的影响。实验结果表明， 随着易电离元素钾含量的增加，所测元素的谱线强度和光谱信背比均是先增加后减小， 当增加到一定含量后，有一个最佳的峰值。为了进一步探讨电感耦合等离子体光源的原 子化和激发机理，测定了不同易电离元素含量条件下光源的激发温度和电子密度。 4. 为了克服基体效应对分析结果准确度的影响，提出了采用标准曲线法和标准加 入法两种定量分析方法优势互补的设想。以台湾乌龙茶叶样品为例，用 ICP-AES 检测 了其中 5 种微量元素，比较分析了两
4、种方法给出的定量结果，并用标准加入法所得数据 对标准曲线法的校正曲线进行修正。 综上所述，不管是在水溶液中加入适量有机添加剂，还是样品经过磁场处理或加入 易电离元素，均可以提高等离子体的电子温度和电子密度，进而提高光源的辐射强度。 这些措施对于降低 ICP-AES 的分析检出限具有非常重要的意义。 关键词 电感耦合等离子体原子发射光谱法 磁处理水溶液 谱线强度 易电离元素 光谱信背比 Abstract II Abstract In this paper, detecting the race elements in water solution by Inductively Coupled P
5、lasma Atomic Emission Spectrometry, the enhancement methods of radiation intensity of ICP was studied. With the rapid development of technology, ICP-AES was extensively applied to the component analysis and the higher level of detection was requested. In order to meet the demand of research and prod
6、uction, some effective measures have been adopted to enhance analysis capacity of spectroscopy instrument so that the detection limit of the analysis were reduced and more accurate analysis results were obtained . These main methods are as follows: 1. The effect of 1-propanol as the addition of samp
7、le on the emission intensity in the ICP was investigated. The results show that the organic addition was obvious enhance radiant intensity of the ICP source and signal-to-background ratios of spectrum. The optimal experiment condition was confirmed. 2. The effect of the electromagnetic field action
8、on the physical property (surface tension and viscosity), nebulization efficiency of sample solution and emission intensity of ICP source. The experimental results show that at magnetic induction intensity is 280mT and magnetization time 10 min, the value of surface tension and viscosity of solution
9、 were significantly reduced and nebulization efficiency was improved, led to emission intensity of great majority elements and signal-to-background ratios were enhanced markedly. The plasma parameter (plasma temperature and electron density) has been measured; the excitation capability of analysis e
10、lements was improved. 3. Easily ionizable element (KCl) was addition to the water solution results of the excitation power of plasma was enhanced. The influence of the different concentration k on the spectral intensity and the signal-to-background ratio of the elements in the samples were studied.
11、The experiment results showed that with the increase of the easily ionizable element concentration, the spectral intensity and signal-to-background ratio were increased at first and then reduced, after that appear a max peak value when reached fixed concentration. In order Abstract III to move forwa
12、rd a single step discusses to the atomization and excitation mechanism of the ICP source, excitation temperature and electron density were measured in the different easily ionizable element concentration. 4. In order to overcome the influence of the matrix effect on the analysis result accuracy, a c
13、omplementary advantages idea of two quantitative analysis methods (standard curve method and standard addition method) was proposed. With tea sample as case, five trace elements were determined using ICP-AES. After comparative results of two analysis methods, the calibration curve from standard curv
14、e method was corrected by the data of method of standard addition. To sum up, the source radiant intensity and the plasma parameter could be increased obviously by the following methods: The appropriate organic solvent or easily ionizable element were added in the water solution; The water solution
15、sample was magnetize action. This is of important vital for the reduction of the analytical detection limits of ICP-AES. Keywords Inductively Coupled Plasma Atomic Emission Spectrometry Magnetize action solution Line intensity easily ionizable element Signal-to-background ratios of spectrum 第 1 章 绪
16、论 1 第 1 章 绪 论 1.1 前言 原子发射光谱分析法（Atomic emission spectrometry, AES） 1-2是通过检测试样中的 原子或离子在一定条件下受到光源的激发而发射的特征光谱来研究物质化学组成以及 成分含量的分析方法， 此方法被应用已达一百多年之久。 1961 年Reed3设计了一种采用 Ar或含Ar的混合气体作为冷却气， 切向通入石英管的较为合理的高频放电装置， 并用碳 棒或钨棒来引燃。 他把这种在大气压下所得到的外观类似火焰的高频无极放电称为电感 耦合等离子炬（Inductively coupled plasma, ICP） 。然而Reed的这项工作引起Greenfield4 和Fassel5等人的极大兴趣，将此ICP装置首次引入到AES中，并分别在 1964 年和 1965 年阐述了他们取得的重要研究成果，创立了电感耦合等离子体原子发射光谱法的新技 术，开创了光谱化学分析领域的新
