Study On Ion-Imprinted Solid-phase Extraction On-line Atomic Spectrometry Analysis And Novel Spectrometry Method

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(â…¢)-ion imprinted silica gel(Er-â…¡SG) sorbent was synthesized by surface imprinting technique.With the virtues of high selectivity and huge adsorption capacity,the Er-â…¡SG offered a fast kinetics for the adsorption and desorption of Er(â…¢),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(â…¡)-ion imprinted silica gel(Cu-â…¡SG) 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(â…¡).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(â…¢)-nitrobenzoic acid- phenanthroline complex.The photoacoustic(PA) amplitude spectra of three complexes of Eu(â…¢) 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.