【作者】 郭佳佳；

【导师】 苏庆德；

【作者基本信息】 中国科学技术大学 ， 分析化学， 2009， 博士

【摘要】 原子光谱技术,特别是原子发射和原子吸收光谱法是痕量金属元素定性、定量检测的有效、准确的现代分析技术手段。然而由于实际环境样品组成复杂、基体干扰严重,常常导致光谱检测结果不准确。对样品进行前处理,包括分离和预富集等,是解决这一问题的关键。近年发展起来的固相萃取技术具有很多优越性,但普通固相萃取材料对于共存离子的选择性差,最新的离子印迹技术可以实现对目标离子的高选择性萃取。离子印迹材料的显著特点是在高温高压等苛刻环境下性能稳定的同时,表现出对模板的高度选择性和特异识别能力。使用此类材料对痕量目标物进行固相萃取预富集以及从复杂基体和其他共存元素中选择性分离目标物,可以有效净化目标物的存在环境,这是普通固相萃取材料所无法实现的。而且离子印迹吸附材料的快速吸附、解吸特点,可以满足在线完成试样前处理,并将经纯化和预富集的试样直接引入原子光谱检测器的要求,实现分析的自动化和智能化。本论文主要研究离子印迹材料的固相萃取技术。成功研制了多种新型离子印迹材料,它们均具有高度的选择性、较大的吸附容量、稳定的化学性质和快速的吸附、解吸能力。将这些离子印迹材料与分析化学仪器联用,实现了复杂环境试样经固相萃取后,原子发射光谱和原子吸收光谱在线检测痕量金属元素。论文还对具有充分发展前景的同步辐射原子荧光和光声光谱分析新方法进行了探索性研究。论文共分七章,各章内容概括如下:第一章:综述原子光谱分析中固相萃取技术的理论、特点和研究进展。阐述了不同类型固相萃取材料的优缺点和应用现状,特别总结了离子印迹技术的特点及其在固相萃取中的应用。第二章:钕离子印迹聚合物的合成及其吸附选择性研究。用本体聚合法合成钕离子印迹聚合物,通过元素分析、红外、热分析和光声光谱法验证了产物的结构,并建立等温吸附模型,确定了吸附过程中的反应控制类型。在构建的竞争吸附环境下,该聚合物仍表现出特异的选择性和模板记忆功能。实现了将此聚合物应用于基体复杂的标准参考物质中,对痕量钕离子的固相萃取和定量分析。第三章:离子印迹硅胶吸附剂对铒离子的在线选择性固相萃取。通过表面印迹技术合成了铒离子印迹硅胶吸附剂,该材料在保留离子印迹材料的高选择性和大吸附容量的优点同时,具有快速的吸附、解吸能力,满足在线预富集与检测要求。建立了离子印迹微柱在线固相萃取-电感耦合等离子体原子发射光谱法检测铒离子系统,并利用此系统对标准参考物质中的痕量铒离子定量分析。第四章:离子印迹硅胶吸附剂对铜离子的在线选择性固相萃取。选择自然界分布广泛的毒重金属铜离子作为模板,新型树型有机物二乙烯三胺为配体,通过表面印迹技术合成了铜离子印迹硅胶吸附剂。并建立了离子印迹微柱在线固相萃取-原子吸收光谱法检测铜离子系统。利用此系统成功地对基体复杂的茶叶样品中痕量铜离子进行了在线分离与分析。第五章:综述原子荧光和光声光谱的理论、特点以及研究现状。分析了原子荧光光谱分析技术目前所面临的问题和解决的途径,总结了光声光谱这一新技术手段在稀土固态配合物的分析中所涉及的研究内容和发展趋势。第六章:同步辐射—原子荧光光谱研究。建立了一套同步辐射原子荧光分析装置,用同步辐射作为原子荧光的激发光源,利用其宽波段可调谐的特点,采集到砷原子在紫外波段的十条激发谱线,探讨了各谱线对应的激发电位和跃迁过程,特别研究了234.99nm处最大激发谱线的产生机理、能级跃迁方式和分析应用前景。第七章:取代基位置对Eu(Ⅲ)三元配合物能量传递影响的光声光谱研究。测定了Eu(Ⅲ)的邻位、间位、对位三种硝基苯甲酸和邻菲咯啉三元固体配合物的光声光谱。从无辐射跃迁角度研究了配体取代基位置的不同对中心离子敏化发光强度和配合物分子内能量传递过程的影响,并建立分子内能量传递模型。更多还原

【Abstract】 Atomic spectrometry,especially atomic emission spectrometry（AES） and atomic absorption spectrometry（AAS） are modern analytical technique with availability and veracity.But AAS and AES are sometimes failing to be used for analysis real and environmental sample with complicated component and interferential matrix.At present,one of the methods to solve the problem is using a sample pretreatment technique including separation and pre-concentration.Solid-phase extraction（SPE）,as a sample pretreatment technique was developed since 1980’s.It had the advantages of analytical speed,simplicity,low cost,safty,no emulsification,flexibility and high pre-concentration factor.But common SPE materials are usually having poor selectivity for separation of coexistent metal ions,which can be solved by ion-imprinting technique.An especially appealing feature of the imprinted polymers is their potential to have the affinity and selectivity analogous to antibodies,while retaining several benefits including stability in harsh environments such as high temperatures and pressures.A particularly promising application of ion-imprinted polymers is the SPE preconcentration of analytes present in trace amouts and the separation from other coexisting species or complex matrix,which may lead to selective environmental clean up of analytes,not achievable by the conventional methods.Furthermore,automation and intellectualization of the whole process can be realized by using SPE materials prepared by ion-imprinting technique for on-line pre-concentration and separation of real environmental samples,subsequently detected by atomic spectrometry.The primary content in this dissertation is the study on ion-imprinted materials for solid-phase extraction.Various novel ion-imprinted materials are prepared,having high selectivity,huge adsorption capacity,stable chemical property and fast adsorption/desorption rate.Trace metal ions in complicated matrix can be detected after on-line preconcentration and separation,with the use of these ion-imprinted materials combined with analytical chemistry instruments.The dissertation also includes some exploring study on novel analytical methods of synchrotron radiation- atomic fluorescence spectrometry and photoacoustic spectrometry,which are techniques full of opportunity.There are seven chapters in this dissertation and the content of each one is as following:Chapter 1:The basic concepts of SPE used in atomic spectrometry are briefly described.After a review of theories and characters of SPE,various application of SPE technique in atomic spectrometry and different types of SPE materials are introduced.Especially give a presentation of contents about ion-imprinting technique and its use in SPE.Chapter 2:Synthesis and selective recognition of neodymium ion-imprinted polymer particles.Neodymium ion imprinted polymer particles were prepared by bulk polymerization.Elemental analysis,FT-IR,thermal analysis and photoacoustic spectrometry were introduced to characterize the production.The model of isothermal adsorption has been built and the style of limit-rate step has also been confirmed.The ion-imprinted polymer particles have unique selectivity and templet memory even in competing absorption environment.The developed method is convenient,selective, sensitive and applicable to the determination of trace neodymium in environmental samples with complicated matrix.Chapter 3:On-line selective solid-phase extraction of erbium with a surface ion imprinted silica gel sorbent.Erbium（Ⅲ）-ion imprinted silica gel（Er-ⅡSG） sorbent was synthesized by surface imprinting technique.With the virtues of high selectivity and huge adsorption capacity,the Er-ⅡSG offered a fast kinetics for the adsorption and desorption of Er（Ⅲ）,which can be used for on-line preconcentration and detection. The system of on-line selective SPE and detection of erbium ions using ICP-AES is constructed.Two certified reference materials were analyzed and the determined values were in a good agreement with the certified values.Chapter 4:On-line selective solid-phase extraction of copper with a surface ion imprinted silica gel sorbent.Copper,which is one of wide spread toxic heavy metals, was chosen as templet ion.Diethylenetriamine,a novel treeing organic reagent,is used as ligand.Copper（Ⅱ）-ion imprinted silica gel（Cu-ⅡSG） sorbent was synthesized by surface imprinting technique and was employed as a selective solid-phase extraction material for on-line preconcentration and separation,then coupled with AAS determination of Cu（Ⅱ）.Two certified reference materials were analyzed and the determined values were in a good agreement with the certified values.The developed method was also successfully applied to the determination of trace copper in tea leaf with satisfactory results.Chapter 5:The basic concepts including theories,characters and current Status of the Study on AFS and PAS are briefly described.The current technical problems of AFS technique and ways to resolve are discussed.The research and development trends in using the new technology tools of PAS for investigate rare-earth solid complexes are summed up.Chapter 6:Study on atomic fluorescence spectrometry excited by synchrotron radiation.The novel approach of atomic fluorescence excited by synchrotron radiation has been presented.The system for synchrotron radiation-atomic fluorescence spectrometry（SR-AFS） is developed and experimental conditions as flow rate, analyte acidity,concentration of pre-reducing and hydrogenation system are optimized.The proposed method is successfully applied to get an excitation spectrum of arsenic.Excitation potentials and possible transitions are investigated.Especially for the prominent line at 234.99nm,the mechanism of generation is discussed and a model of energy transition processes is proposed.Chapter 7:Spectra study on the effect of substituent on the energy transfer of Eu（Ⅲ）-nitrobenzoic acid- phenanthroline complex.The photoacoustic（PA） amplitude spectra of three complexes of Eu（Ⅲ） combined with nitrobenzoic acid（NBA） and phenanthroline（Phen）[Eu（p-NBA）₃·Phen,Eu（m-NBA）₃·Phen and Eu（o-NBA）₃·Phen] have been measured,and the PA phase of the different complexes have been calculated.Both the PA amplitude spectra and the luminescence spectra reflect the variation of the luminescent properties,and the PA phase is directly relative to the relaxation time.The effects of nitrate substituent on the molecular structure and energy gap of the complexes have been studied by PA phase and luminescence spectra.更多还原