Dissertation > Excellent graduate degree dissertation topics show

Study of Solid-Phase Extraction Coupled with Atomic Spectrometry for Separation and Preconcentration of Trace Metal Ions with Microcrystalline Anthracene

Author: WangXu
Tutor: LiQuanMin
School: Henan Normal
Course: Analytical Chemistry
Keywords: Microcrystalline Anthracene Selective reagents Co(Ⅱ) Cu(Ⅱ) Zn(Ⅱ) Mo(Ⅵ) Solid-Phase Extraction
CLC: X832
Type: Master's thesis
Year: 2011
Downloads: 3
Quote: 0
Read: Download Dissertation

Abstract


Along with the rapid development of science and technology, higher requirements have been put forward for analytical science. Selective separation and enrichment for metal ion is a hot spot within analytical chemistry. Since the low amounts of targets in environmental samples or the complexity of samples’components, modern instruments with high resolution are helpless for determining trace element in water samples directly. It is necessary to separate and enrich trace element before determination. Owing to its advantages of high efficiency, little sample amount, low cost and simple operation, solid phase extraction is widely recognized as an effective technology. This thesis includes five sections. In the first section, recent study concerning solid phase extraction has been summarized, features and advantages of microcrystalline anthracene used as solid phase extractant are illustrated. Then developing trend has also been analyzed. During the following four sections, the new extraction system based on microcrystalline anthracene as the adsorbent has been applied in the separation and enrichment of trace Co(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Mo(Ⅵ) etc. in water samples. Furthermore, thermodynamic and kinetic behaviors of Zn(Ⅱ) and Mo(Ⅵ) adsorption onto microcrystalline anthracene and related adsorption mechanism have been investigated in this paper.A advanced method using microcrystalline anthracene as adsorbent for preconcentration and determination of trace Co(Ⅱ) in environmetal water sample is developed in Chapter Two. Under the optimum conditions, the chelate complex, which is formed by Co(Ⅱ) and 1-nitroso-2-naphthol, is quantitatively adsorbed onto the surface of microcrystalline anthracene. Co(Ⅱ) enriched is then eluted with 6.0 mol·L-1 of HCl and then determined by Microwave Plasma Torch Optical Emission Spectrometry (MPT-OES). This method has been applied successfully in the separation and enrichment of Co(Ⅱ) in environmetal water samples. The recovery is achieved between 93.3% and 106.9% and R.S.D is less than 2.8%. Enrichment factor reached a high of 200 which shows the method with high accuracy and sensitivity. During the third section, we have used microcrystalline anthracene loaded with 1-(2-pyridylazo)-2-naphthol (PAN) as solid phase extractant and successfully for the pretreatment of trace copper(Ⅱ) in diverse natural samples. In the presence of NaCl, neutral molecule of Cu(PAN)Cl is formed by Cu(Ⅱ) and PAN, and it is adsorbed on the microcrystalline anthracene by intermolecular force. Under certain conditions, the aim of Cu(Ⅱ) separation from other transition metal ions, for instance, Cd(Ⅱ), Co(Ⅱ), Mn(Ⅱ), Pb(Ⅱ), Zn(Ⅱ), Cr(ⅡI), Fe(ⅡI), Al(ⅡI), can be achieved. This method having the merits of environmental friendly, high efficiency, simple operation, good selectivity has been applied in the pretreatment and determination of trace Cu(Ⅱ) in diverse environmental samplesThe main content of section four is the separation and enrichment of Zn(Ⅱ) in environmetal samples with microcrystalline anthracene loaded with 8-hydroxyquinoline (HOx) as solid phase extractant. The chelate of Zn(Ox)2 generated by Zn(Ⅱ) and 8-hydroxyquinoline can be quantitatively adsorbed on the microcrystalline anthracene. However, Hox can also react with other metal ions in the environmental sample. In order to separate the enriched Zn(Ⅱ), 0.50 mol·L-1 NaOH is selected as eluant. Due to its amphoteric nature, Zn(Ⅱ) was desorbed into the solution in the form of ZnO22- in the alkali medium, by contrast, Cu(Ⅱ), Co(Ⅱ), Cd(Ⅱ), Mn(Ⅱ), Ni(Ⅱ) etc. form precipitates as hydroxide. Therefore, the aim of selective separation of Zn(Ⅱ) from other ions can be achieved. Thermodynamic and kinetic models of Zn(Ⅱ) adsorption onto microcrystalline anthracene and related adsorption mechanism have been investigated in this paper. Condition solubility products between 8-hydroxyquinoline and other heavy metal ions, such as Cu(Ⅱ), Co(Ⅱ), Cd(Ⅱ), Ni(Ⅱ), Fe(ⅡI) under the same experimental conditions are calculated. It is showed that by optimizing experimental conditions, this system can probable be used for separation and enrichment of the ions metioned above, which is persuasive that microcrystalline anthracene has great potential and wide prospect for separation and enrichment of metal ions.In Chapter Five, we have studied that microcrystalline anthracene loaded with 8-hydroxyquinoline for the separation and enrichment of trace Mo(Ⅵ) in environmental water samples and determination of Mo(Ⅵ) by MPT-OES. As far as we know, the study concerning microcrystalline anthracene used for the separation and enrichment of trace Mo(Ⅵ) is reported for the first time in this thesis. Related adsorption mechanism and thermodynamic and kinetic modles have been discussed detailed. Experimental conditions are also optimized. As pH<5.00, Mo(Ⅵ) in the form of MoO22+ can react with HOx to form the chelate complex of MoO2(Ox)2 which is adsorbed onto the surface of microcrystalline anthracene by intermolecular force. This method, with the advantages of fast adsorption equilibrium, easy elution, good adsorption capacity, favorable reproducing property, accessibility and low cost, will probable attract more attention in the field.

Related Dissertations

  1. Preparation, Evaluation, and Application of Several Natural Product Molecularly Imprinted Polymers,R284.1
  2. The Application of Eggshell Membrane for Solid-phase Extraction and the Determination of Trace Metal Elements in Environment Water,X832
  3. Study on Separation、 Preconcentration and Analysis of Trace Elements with Carbon Nanometer Materials,TB383.1
  4. Studies on the Detection Methods of Virginiamycin in Feed,S816.17
  5. Electrochemical Studies on Interaction between ApoCopC、BSA and Cu(Ⅱ)、Cu(Ⅰ)、Cd(Ⅱ)、Ag(Ⅰ),O646
  6. Imprinted Polymer Preparation and application of solid-phase extraction,O631.3
  7. The Study on Endocrine Disrupting Chemicals Removal Features in Ping Shan Tou Waterplant of Huainan City,TU991.2
  8. Alternatives to ozone-depleting substances in the environment of trifluoroacetic acid degradation products,O657.71
  9. Cu (Ⅱ) imprinted chitosan crosslinked Membrane and adsorption studies,TB383.2
  10. Study of Exposure Level and Exposure Factors of Phthalate Esters in Pregnant Women,R714.2
  11. Preparation of Dummy Template Imprinted Polymers at Surface of Silica Submicroparticles for the Selective Extraction of Trace Bisphenol a from Water Samples,X832
  12. GC / MS analysis of environmental pollutants in the marine ecosystem and applied research in the field of,X502
  13. Determination of Benzimidazoles Residues in Foodstuffs by HPLC-MS/MS,O657.63
  14. Β - lactam antibiotic residues in food of animal origin by ultra performance liquid chromatography - tandem mass spectrometry method,TS207.53
  15. Preparation of nano - silica surface molecularly imprinted polymer and its application in the chlorpyrifos pesticide residues detection,TQ450.263
  16. The pyrethroid pesticide immune and chromatographic analysis method,TQ450.2
  17. Study on Preparation of Norfloxacin Molecularly Imprinted Polymers and Its Application in Solid Phase Extraction Technology,O631.3
  18. Study on Preparation and Application of estradiol-imprinted Microspheres Using Modified Precipitation Method,O631.3
  19. Study on the Preparation Methods and Recognition Properties of Fluoroquinolones-Molecularly Imprinted Sol-Gel Sorbents,TQ424
  20. Application of Single-Wall Carbon Nanotubes for Elemental Speciation,O613.71

CLC: > Environmental science, safety science > Environmental Quality Assessment and Environmental Monitoring > Environmental monitoring > Water quality monitoring
© 2012 www.DissertationTopic.Net  Mobile