Dissertations / Theses on the topic 'Ion exchange chromatography'
To see the other types of publications on this topic, follow the link: Ion exchange chromatography.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Ion exchange chromatography.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Polite, Lee Nicholas. "Studies in ion exchange chromatography." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/54338.
Full textAbstract:
This dissertation investigates three major problems in IC, ranging from the practical to the theoretical. The first is of interest to the field of quantitative analysis. Since ion chromatography is primarily a quantitative technique, the linear range of the detector is of particular interest. The linear range was determined to be nearly five orders of magnitude for several common ions. The probes used were fluoride, chloride, sulfate, sodium, and potassium with concentrations ranging from 10 ppb to 1000 ppm. This portion of the dissertation describes the first attempt made to elucidate the linear detection range in ion chromatography using micro-membrane suppression.
The Iinearity experiments demonstrate the versatility of ion chromatography with respect to quantifiable concentrations. However, a major problem is encountered when attempting to determine a trace ion concentration in the presence of a high concentration of a similarly charged ion (matrix ion). The second part of this dissertation offers a solution to this problem. In ion chromatography, the large excess of a matrix ion affects not only the ions expected in that region of the chromatogram, but also destroys the chromatographic exchange process. One objective of this study was to develop a rapid quantitative method to determine 5 ppm chloride in the presence of 100,000 ppm sulfate. A standard anion exchange column will completely lose resolution between chloride and sulfate at a sulfate concentration of approximately 2500 ppm. The apparatus designed and built by the author uses two analytical ion—exchange columns coupled in series by a high pressure switching valve. ln order to complete the system, the author designed and built y a high pressure conductivity detector cell to monitor the conductivity of the effluent from the first column. The system works by overloading the first column and then allowing the effluent to pass onto the second column. When the trace chloride in on the second column, the first column is switched out of line. This process allows the trace chloride to be separated from the residual sulfate.
The column switching study brought to light several theoretical questions about the inner workings of the packing materials used in ion chromatography. These questions include the effects that flow rate and temperature have on capacity and efficiency in ion chromatography separations. Using chloride and sulfate as probes, the chromatographic efficiency was shown to decrease from 30° to 60° C. Even more surprising was the result that sulfate retention increased with increasing temperature while chloride retention decreased under the same conditions. Detailed studies as well as possible explanations are included in the third part of this dissertation.Ph. D.
2
Cao, Liming. "Protein Separation with Ion-exchange Membrane Chromatography." Link to electronic thesis, 2005. http://www.wpi.edu/Pubs/ETD/Available/etd-050405-174109/.
Full text
3
Maketon, Supachai. "Methods Development for Ion Chromatography." Thesis, North Texas State University, 1986. https://digital.library.unt.edu/ark:/67531/metadc330927/.
Full textAbstract:
Ion chromatography (IC) as developed by Small et. al. in 1975 has become an efficient and reliable analytical technique for simultaneous analysis of multiple ions in solution. The principle requirement prior to use the IC for an analysis is sample preparation; these include sample decomposition, solvent extraction, and trapping in case the target element is in the gas phase, etc. Solvent extractions for fluoride, chloride, sodium, ammonium, and potassium ions which are soluble in soils are described. Sample decompositions include silicate rocks using hydrofluoric acid for the determination of phosphorus; organic pesticides using lithium fusion technique for the determination of halide and cyanide ions are also described. After these sample preparation techniques, the aqueous solutions obtained were analyzed on the ion chromatograph for the analyses of the anions and cations mentioned above. Recovery and reproducibility of each technique is in general quite good and the comparison between the results obtained from the IC method and other instrumentation are given.
4
Forrer, Nicola. "Antibody purification with ion-exchange chromatography." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17784.
Full text
5
Galindo, Irma C. (Irma Concepcion). "Investigation Into the Causes for the Loss of Resolution in an Ion Chromatograpy Resin." Thesis, North Texas State University, 1988. https://digital.library.unt.edu/ark:/67531/metadc798197/.
Full textAbstract:
Four mechanisms were considered as possible causes of the loss in resolution for a Dionex CG2 ion chromatography resin: 1) presence of inorganic ions strongly bound to the active sites; 2) adsorption of organic species; 3) physical alterations; and 4) chemical alterations. The instrumental analyses used to gather data were ICP, FT-IR, SEM, solid C-13 NMR and IC. Based on the results, no metal ions are bound to the resin, no organic species are held onto the resin, and no physical change was observable. The cause for the loss of resolution is a strong reduction in the number of active sites in the resin as confirmed by elemental analysis for the sulfur in the sulfonic acid present in the active sites.
6
Pearson, C. H. G. "New ion exchange resins for ion chromatography applied to anions." Thesis, University of Kent, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372771.
Full text
7
Allyn, M. Liz. "Indirect photometric chromatography of iodide ion in aqueous solutions /." Online version of thesis, 1987. http://hdl.handle.net/1850/8769.
Full text
8
Huang, Julie Shiong-Jiun. "Ion Chromatography of Soluble Cr(III) and Cr(VI)." Thesis, University of North Texas, 1988. https://digital.library.unt.edu/ark:/67531/metadc500410/.
Full textAbstract:
Ion chromatography coupled with a conductivity detector was used to investigate the analysis of Cr(III) and Cr(VI) in aqueous samples. An IC methodology for Cr(III) was developed using a cation column and an eluent containing tartaric acid, ethylenediamine, and acetonitrile at pH 2.9. The detection limit of this method can reach 0.1 ppm level with good precision. Several operational parameters were evaluated during the regular use of the method. Comparison of the IC method with AA method showed good agreement between the two methods. The anion exchange column was used for Cr(VI) determination. The best results were obtained with an eluent containing sodium gluconate, borate buffer, glycerin, and acetonitrile. The retention time for the Cr207 2 - sample was 11 min. and the calibration curve was linear between 1.0 and 100 ppm.
9
Borghi, Andrea. "Cellulose hollow fibers membranes for ion-exchange chromatography." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20289/.
Full textAbstract:
The development of an efficient and cost-effective purification process is the objective of protein separation. Usually, the most common procedure is chromatography, typically performed in a packed bed column; however, the cost is relatively high.
Nowadays, one of the most interesting and promising method is the employment of particular membranes, the hollow fibers, in the standard chromatographic operations. Hollow fibers membranes were developed in the 1960s, specifically for reverse osmosis; nonetheless, they are now largely applied in both liquid and gaseous applications.
In this project, the preparation of cellulose hollow fibers, exploited for ion-exchange chromatography, was studied during a five months internship at the King Abdullah University of Science and Technology (KAUST) in the group of Professor Suzana Nunes.
The hollow fibers were prepared, dissolving cellulose in 1-Ethyl-3-methylimidazolium diethyl phosphate (EMIM DEP), an ionic liquid commonly used as green solvent for cellulose.
After a first research, regarding the performance of flat sheet membrane obtained by phase inversion, in which permeance and rejection were investigated using bovine serum albumin (BSA), the second phase of the project was the optimization of cellulose hollow fibers. Steps of the procedure included: a prior functionalization and application in ion-exchange chromatography. Ion exchange hollow fibers were, indeed, prepared reacting the cellulose with 1,4-butane sultone, and checked for proper functionalization by FTIR.
The ion-exchange fibers were primarily characterized in bind and elute mode using pure lysozyme solutions. The Tris buffer, chosen for equilibration and adsorption, was optimized in terms of molarity and pH.
The values of static binding capacity resulted in promising and comparable to that of the commercial ion-exchange membrane.
10
McCannel, Anne Marie. "Separation of immunoglobulins from egg yolk using metal chelate interaction chromatography and ion exchange chromatography." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/27987.
Full textAbstract:
The immune response of chickens immunized with β-N-acetylglucosaminidase was monitored in the egg yolks of the birds using an enzyme-linked immunosorbent assay. Significantly higher levels of specific antibodies were detected in the yolks of the birds immunized with the enzyme when compared with the yolks of a control bird collected over the same period significant differences also were found in the response within the immunized group of birds, indicating individual variability to the injections.
Immunoglobulins were isolated from egg yolk after a preliminary purification using alginate to precipitate lipoproteins. A ten millilitre DEAE-Sephacel ion exchange chromatography column resulted in a final product containing 16 mg of IgG with a purity of 60% when 50 mL of an egg yolk supernatant was applied. Specific antibody activity toward the antigens β-lactoglobulin and E. coli lipopolysaccharide was higher in both cases in the isolated immunoglobulin fractions which contained lower purity (40%). Lower antibody activity was observed in the 60% purified fractions. Separation of specific antibodies from non-specific antibodies appeared to occur, possibly due to the given characteristics of the specific antibodies, or due to the differences exhibited by chicken IgG subpopulations.
Using metal chelate interaction chromatography, a 10 mL copper-loaded column was able to yield 104 mg of IgG with a purity of 75% when 200 mL egg yolk supernatant was applied. Again, the heterogeneous nature of chicken IgG was illustrated.
A comparison of the two chromatographic techniques indicated the advantages of metal chelate interaction chromatography over ion exchange chromatography under the conditions examined.
Applications of the chicken IgG isolated by metal chelate interaction chromatography to an enzyme-linked immunosorbent assay for the detection of β-N-acetylglucosaminidase was attempted. Linear relationships were obtained when standard solutions of the enzyme were used in the assay. The results indicate that MCIC-isolated chicken immunoglobulins have excellent potential for use in analytical tests.Land and Food Systems, Faculty of
Graduate
11
Langford, John F. Jr. "Effects of adsorbent structure and adsorption on transport phenomena in ion-exchange chromatography." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 250 p, 2007. http://proquest.umi.com/pqdweb?did=1251904681&sid=1&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Full text
12
Pribyl, Ondrej. "Modelling of electrochemical ion exchange." Thesis, University College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325234.
Full text
13
Naidoo, Clive. "Selective separation of elements and radioisotopes by ion exchange chromatography." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/53046.
Full textAbstract:
Thesis (PhD)--Stellenbosch University, 2002.ENGLISH ABSTRACT: The equilibrium distribution coefficients of 32 metal ions [Al(llI), As(V), CdïIl), Ce(III), Ce(IV), Co(n), Cr(III), Cu(II), Fe(III), Ga(III), Ge(IV), !n(III), La(III), Mn(II), Mo(VI), Nb(V), Ni(II), Pr(III), Sb(V), Sc(III), Se(IV), Sn(IV), Ta(V), Tb(III), Te(IV), Ti(IV), Vev), W(VI), Y(III), Yb(III), Zn(lI) and Zr(IV)] on a cation exchanger (Bio- Rad® AG50W-X8) and an anion exchanger (Bio-Rad® AG1-X8) in varying oxalic acid - sulphuric acid mixtures were successfully determined. The equilibrium distribution coefficients of these selected metal ions were determined in both 0.05 M and 0.25 M oxalic acid at various concentrations of sulphuric acid (0.005 M, 0.05 M, 0.10 M, 0.25 M, 0.50 M, 1.00 M, 1.50 M and 2.00 M). Attempts to explain the sorption behaviour of the selected metal ions were made by using MINEQL+, a speciation modelling program, and the speciation systems for AI(III), Cd(II), Co(II) and Zn(lI) in varying oxalic acid - sulphuric acid mixtures were determined. Two component [Zr(IV)-La(III); AI(III)-La(III); Ga(IlI)-Zn(II); As(V)-Zn(II); Cu(II)- Ce(IV); Ga(III)-Ce(IV); Ge(IV)-Ce(III); Mo(VI)- Y(III); Nb(V)- Y(III); Ga(III)-Co(II); As(V)-Co(lI) and Fe(III)-Mn(II)] and three component [Fe(III)-Ga(III)-Zn(lI) and Zr(IV)-Ta(V)-Yb(III)] mixtures on a 10 ml or 13 ml cation exchange resin in a variety of oxalic acid - sulphuric acid mixtures were successfully separated. Two component [As(V)-Zr(IV); Co(II)-Fe(III); Ni(II)-Co(lI) and Ni(II)-Fe(III)] and three component [Ni(II)-As(V)-Se(IV); AI(III)-Zn(II)-Ge(IV) and As(V)-Cu(II)-Ge(IV)] mixtures on a 10 ml or 13 ml anion exchange resin in a variety of oxalic acid - sulphuric acid mixtures were also successfully separated and studied. It was also shown how some of the elution curves developed above could easily be adapted for radiochemical separations. Usin~ the relevant data from the above study, a separation for 68Gefrom a Ga20 target was developed according to a method based on acid dissolution of the target and chromatography on an anion exchange resin (Bio-Rad® AG1-X8). The separated 68Geshowed high radionuclidic purity and an acceptable chemical purity.
AFRIKAANSE OPSOMMING: Die ewewigsverdelingskoëffisiënte van 32 metaalione [Al(III), As(V), Cd(II), Ce(III), Ce(IV), Co(II), Cr(III), Cu(II), Fe(III), Ga(III), Ge(IV), In(III), La(III), Mn(ll), Mo(VI), Nb(V), Ni(ll), Pr(Ill), Sb(V), Sc(III), Se(IV), Sn(IV), Ta(V), Th(Ill), Te(IV), Ti(IV), vrv; W(VI), Y(III), Yb(III), Zn(lI) en Zr(IV)] op 'n katioonruiler (Bio-Rad® AG50W-X8) en 'n anioonruiler (Bio-Rad® AG1-X8) in veranderende oksaalsuurswaelsuurmengsels is met welslae bepaal. Die ewewigsverdelingskoëffisiënte van hierdie geselekteerde elemente is in beide 0.05 Men 0.25 M oksaalsuur by verskeie konsentrasies swaelsuur (0.005 M, 0.05 M, 0.10 M, 0.25 M, 0.50 M, 1.00 M, 1.50 M en 2.00 M) bepaal. Daar is gepoog om die sorpsiegedrag van die geselekteerde metaalione te verklaar deur die gebruik van MINEQL+, 'n spesiëringmodelleringsprogram, en die spesiëringsisteme vir AI(III), Cd(II), Co(II) en Zn(lI) in veranderende oksaalsuur-swaelsuurmengsels is bepaal. Tweekomponent [Zr(IV)- La(III); AI(III)-La(II!); Ga(III)-Zn(Il); As(V)-Zn(II); Cu(II)-Ce(IV); Ga(III)-Ce(IV); Ge(IV)-Ce(Il!); Mo(VI)- Y(III); Nb(V)- Y(ll!); Ga(Ill)-Co(Il); As(V)-Co(lI) en Fe(III)- Mn(II)] en driekomponent [Fe(III)-Ga(III)-Zn(ll) en Zr(IV)- Ta(V)- Yb(III)] mengsels op 'n 10 ml of 13 ml katioonruilhars in 'n verskeidenheid oksaalsuurswaelsuurmengsels is met welslae geskei. Tweekomponent [As(V)-Zr(IV); Co(II)- Fe(III); Ni(Il)-Co(lI) en Ni(II)-Fe(III)] en driekomponent [Ni(II)-As(V)-Se(IV); AI(III)-Zn(Il)-Ge(IV) en As(V)-Cu(II)-Ge(IV)] mengsels op 'n 10 ml of 13 ml anioonruilhars in 'n verskeidenheid oksaalsuur-swaelsuurmengsels is ook met welslae geskei en bestudeer. Daar is ook aangetoon hoe sommige van die elueringskrommes wat hierbo ontwikkel is, maklik vir radiochemiese skeidings aangepas sou kon word. Deur gebruik te maak van die relevante data uit die studie hierbo, is 'n skeiding vir 68Geuit 'n Ga20-teiken ontwikkel volgens 'n metode gebaseer op suurdissolusie van die teiken en chromatografie op 'n anioonruilhars (Bio-Rad® AG1-X8). Die geskeide 68Gehet hoë radionukliedsuiwerheid en 'n aanvaarbare chemiese suiwerheid getoon.
14
Colby, Christopher Brett. "Optimisation of scale-up of chromatography /." Title page, table of contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phc686.pdf.
Full text
15
Chokazinga, Davlin. "Coordination studies of inositols with aluminium and related cations." Thesis, Curtin University, 2003. http://hdl.handle.net/20.500.11937/2003.
Full textAbstract:
In this work cis-inositol, epi-inositol and myo-inositol carbonate were successfully synthesised and used for coordination studies. The preparation of cis-inositol was achieved by reduction of tetrahydroxybenzoquinone via hydrogenation with palladium hydroxide as the catalyst and was purified by chromatographic separation using Dowex resin. The synthesis of epi-inositol was achieved by the nitric acid oxidation of myo-inositol to form epi-inosose which was subsequently reduced by hydrogenation using palladium hydroxide as the catalyst. myo-Inositol was converted into its mono-orthoformate derivative and the equatorial hydroxy group was then protected as a tertiary-butyldimethylsilyl ether. The carbonate group was introduced onto this protected inositol and then the protecting groups were removed by acid hydrolysis. The coordination characteristics of four inositols, viz cis-inositol, epi-inositol, myo-inositol and myo-inositol carbonate with calcium, aluminium, gallium, lanthanum and samarium ions have been investigated. Interactions of the aluminate anion with epi-inositol and myo-inositol in deuterated sodium hydroxide were also investigated. Three methods were used in the study of complexation behaviour of these systems. namely, [superscript]13C NMR spectroscopy, HPLC and ion exchange chromatography. [superscript]13C NMR spectroscopy was found to be most useful for determining possible complexation behaviour of the inositols. Chemical shift changes of the resonance signals in the [superscript]13C NMR spectra on sequential addition of cations to solutions of the inositols at near neutral pH, have led to determination of possible coordination sites of the inositols. In general, large induced chemical shift changes have been interpreted to signify strong cation-inositol interaction at specific hydroxy groups.Triaxial sites of the inositols have shown a preference to coordinate small ions with ionic size of at least 60 pin, smaller ions than this displayed very weak interactions. Likewise large ions (90-100 pm) imparted weak interactions on triaxial sites of the inositols. These large ions coordinated well with the axial-equatorial-axial sites of the inositols although it was observed that calcium ions appeared to form a 2:1 ligand:cation complex with cis-inositol at the triaxial site despite being a large cation (100 pm). The detection of complex formation by HPLC showed a possible formation of very stable complexes of epi-inositol complexes with calcium ions. However, a change of refractive index of the solution on sequential addition of the cation may have caused an interference in the results such that direct interpretation was not possible. Ion exchange chromatography provided the quickest guide on how strongly the inositols interact with a particular cation. However, determination of complex stoichiometry and or structure was not possible using this technique.
16
Trilisky, Egor. "Stationary and mobile phase selection for ion-exchange chromatography of viruses." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 266 p, 2009. http://proquest.umi.com/pqdweb?did=1674096451&sid=1&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Full text
17
Kumar, Guneet. "Design of anion exchange cellulose hydrogel for large proteins." Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06062008-163945/.
Full text
18
SENEDA, JOSE A. "Comportamento de cobre (II) e uranio (VI) em cromatografia de precipitacao no sistema resina anionica forte-hexacianoferrato (II)." reponame:Repositório Institucional do IPEN, 1997. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10489.
Full textAbstract:
Made available in DSpace on 2014-10-09T12:41:03Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:10:17Z (GMT). No. of bitstreams: 1 04033.pdf: 2633354 bytes, checksum: f9347be894a819791c1c4ebbed150b1e (MD5)
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
19
Arcanjo, Maria Rosiene Antunes. "Study on the adsorption of lactic acid by ion exchange chromatography." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13346.
Full textAbstract:
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoCurrently the demand for renewable fuels has increased a lot. Thus, biodiesel is an alternative to oil and its derivatives, since its production is cheaper, there is a reduction in emissions, and is considered a renewable energy. Due to government incentives that drive the production of biodiesel, such fuel has been produced on a large scale. Of all the raw material used for producing biodiesel via transesterification, 10 % in mass is converted into glycerin, excess demand and absorption capacity of the current markets. In this context, it is of fundamental importance to develop alternative technologies and innovative at the same time to consume this surplus of crude glycerin. The production of lactic acid by hydrothermal conversion of glycerol is an alternative that adds significantly to the productivity of the biodiesel industry value, besides the production of an organic acid that is widely used industrially. This organic acid exists as two optical isomers, D - lactic acid and L- lactic acid. Presently, it has become an important monomer in the plastics industry, and polymerized biodegradable plastics such as poly-L- lactic acid and copolymers of lactic acid. Therefore, there is a continued interest in a more efficient process for the production of lactic acid as well as for their recovery and purification. Thus, the aim of this study was to conduct a study on the adsorption of lactic acid (derived from the conversion of glycerol resulting from biodiesel production) by ion exchange by Amberlite IRA 67 and IRA 96. Different eluents were evaluated at various concentrations in order to obtain a higher efficiency in removing lactic acid adsorbents studied. From the breakthrough curves obtained with different concentrations of lactic power (60-302 g/L) acid the adsorption isotherms were constructed at temperatures of 30 ÂC, 40 ÂC and 60 ÂC. With data from lactic acid concentration for each condition studied, became the model fit the Langmuir adsorption isotherm. Studies on the purification column fixed bed with mono-component solutions, binary mixtures and real mixture were also performed. It was concluded that the application of the proposed methodology for the purification of lactic acid in a fixed-bed column showed better results when the condition (temperature = 30 ÂC) was used in both adsorbents. As the Amberlite IRA 96, the adsorbent showed better performance in the adsorption of lactic acid.
Atualmente a procura por combustÃveis renovÃveis tem aumentado muito. Deste modo, o biodiesel surge como alternativa em relaÃÃo ao petrÃleo e seus derivados, jà que sua produÃÃo à mais barata, hà uma diminuiÃÃo na emissÃo de poluentes, e à considerada uma energia renovÃvel. Devido aos incentivos governamentais que impulsionam a produÃÃo de biodiesel, tal combustÃvel tem sido produzido em larga escala. De toda a matÃria-prima utilizada para a produÃÃo de biodiesel, atravÃs de transesterificaÃÃo, 10% em massa à convertida em glicerina, excedendo a demanda e capacidade de absorÃÃo dos mercados atuais. Neste contexto, à de fundamental importÃncia o desenvolvimento de tecnologias alternativas e ao mesmo tempo inovadoras para consumir este excedente de glicerina bruta. A produÃÃo de Ãcido lÃtico por conversÃo hidrotÃrmica do glicerol à uma alternativa que agrega um valor significativo para a produtividade da indÃstria de biodiesel, alÃm da produÃÃo de um Ãcido orgÃnico que à amplamente utilizado industrialmente. Esse Ãcido orgÃnico existe como dois isÃmeros Ãpticos, D-Ãcido lÃtico e L-Ãcido lÃtico. Atualmente, tem se tornado um importante monÃmero na indÃstria de plÃsticos, sendo polimerizado em plÃsticos biodegradÃveis, tal como poli-L-Ãcido lÃtico e seus copolÃmeros de Ãcido lÃtico. Por isso hà um interesse contÃnuo em um processo mais eficiente para a produÃÃo de Ãcido lÃtico, assim como para a sua recuperaÃÃo e purificaÃÃo. Dessa maneira, o objetivo desse trabalho foi realizar um estudo sobre a adsorÃÃo de Ãcido lÃtico (oriundo da conversÃo do glicerol resultante da produÃÃo do biodiesel) por cromatografia de troca iÃnica pelas resinas Amberlite IRA 67 e IRA 96. Foram avaliados diferentes eluentes em concentraÃÃes diversas, afim de se obter uma maior eficiÃncia na remoÃÃo de Ãcido lÃtico dos adsorventes estudados. A partir das curvas de ruptura obtidas com diferentes concentraÃÃes de alimentaÃÃo de Ãcido lÃtico (60-302 g/L) foram construÃdas as isotermas de adsorÃÃo nas temperaturas de 30ÂC, 40ÂC e 60ÂC. Com os dados de concentraÃÃo de Ãcido lÃtico para cada condiÃÃo estudada, fez-se o ajuste do modelo da isoterma de adsorÃÃo de Langmuir. Estudos sobre a purificaÃÃo em coluna de leito fixo com soluÃÃes monocomponentes, misturas binÃrias e mistura real tambÃm foram realizados. Concluiu-se que a aplicaÃÃo da metodologia proposta para purificaÃÃo do Ãcido lÃtico em coluna de leito fixo mostrou melhores resultados quando a condiÃÃo (temperatura=30ÂC) foi utilizada em ambos os adsorventes. Sendo a resina Amberlite IRA 96, o adsorvente que mostrou melhor eficiÃncia na adsorÃÃo do Ãcido lÃtico.
20
Jones, Vonda K. (Vonda Kaye). "Methods Development for Simultaneous Determination of Anions and Cations by Ion Chromatography." Thesis, North Texas State University, 1987. https://digital.library.unt.edu/ark:/67531/metadc330724/.
Full textAbstract:
The problem with which this research is concerned is the determination of inorganic anions and cations with single injection ion chromatography. Direct detection of the separated analyte ions occurs after the analyte ions have passed through ion-exchange resins where they are separated according to their affinity for the ion-exchange resin active sites. The techniques involve the use of essentially a non-suppressed ion chromatographic system followed by a suppressed ion chromatographic system. With this system it is possible to accomplish both qualitative and quantitative determinations.
21
Ball, James William 1945. "Thermodynamic and isotopic systematics of chromium chemistry." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/191202.
Full textAbstract:
This investigation has produced four major results: (1) Thermodynamic properties of chromium metal, aqueous ions, hydrolysis species, oxides and hydroxides were compiled. Data were critically evaluated, some data were recalculated, and thermodynamic properties were selected. (2) A method was developed for separating chromium from its natural water matrix using sequential anion and cation exchange chromatography. (3) A method for determining the ⁵³Cr/⁵²Cr ratio using solid-source thermal ionization mass spectrometry with the silica gel-boric acid ionization- - enhancement technique was developed. (4) Ground water samples from six locations were analyzed for their ⁵³Cr/⁵²Cr ratio using the above methods. Results from carefully measured electromotive force (emf) values for the reduction of Cr³⁺ to Cr²⁺ were recalculated for compatibility with the infinite dilution standard state, and a revised ∆G°(f) for Cr²⁺(aq) was calculated. Equilibrium constants for chromium(III) hydrolysis were taken from Rai, et al. (1987) and for chromium(VI) hydrolysis from Palmer, et al. (1987). The ion exchange method is based on retention of chromium(VI) on strongly basic anion exchange resin at pf1 4 and its reductive elution with 2N HNO₃ . Chromium(III) is retained on strongly acidic cation exchange resin at pH 1.3 and eluted with 5N HNO₃. Possible interferents include metals that form both oxyanions and cations. High-purity reagents and containers made of rigorously cleanable noncontaminating materials are required. Samples for mass spectrometry are pretreated with aqua regia and concentrated nitric acid, then mixed with silica and boric acid and transferred to the tantalum filament of a stainless steel and glass sample holder. The ⁵³Cr/⁵²Cr ratio was measured to avoid isobaric interferences with iron. To be significantly different from each other, isotopic signatures must differ by at least 0.5 per mil. Samples from six locations were examined for their ⁵³Cr/⁵²Cr ratio. For the samples with natural origin, the spread in δ⁵³Cr values of-2.0 to +3.0 per mil suggests that samples of chromium derived from differing source materials or from different geographic locations have distinct isotopic signatures. Conclusions regarding source-related variations in the isotopic signature of contaminant chromium are problematic, because specific information about the respective source materials is lacking.
22
Martin, Bertha Louise. "High pressure liquid chromatography ion exchange studies on bile relating to the postmortem interval." Scholarly Commons, 1987. https://scholarlycommons.pacific.edu/uop_etds/2141.
Full textAbstract:
It is the purpose of this, then, to investigate the feasibility of using the changes of concentrations of small iconic decomposition products in bile as indicators of time since death. High pressure liquid chromatography was selected for measurement of these changes.
23
Pannell, Daniel K. (Daniel Kirk). "Detector Comparison for Simultaneous Determination of Organic Acids and Inorganic Anions." Thesis, University of North Texas, 1988. https://digital.library.unt.edu/ark:/67531/metadc500456/.
Full textAbstract:
The research reported here is a study of detector systems to determine those most suited for simultaneous organic acid, inorganic anion determination. Comparisons are made on the basis of detection limits and sensitivities for conductivity, UV/Vis, photoconductivity, and derivative conductivity detection systems. The investigation was made using a constant chromatographic system with the only variable component being the detector system. Eluant optimization conditions for each detector are reported along with tables reporting detection limits and sensitivities for each detector system. Various chromatograms are also shown to provide a visual comparison between detector results.
24
Kouyoumdjian, Arthur Jean Michel. "The functionalisation and application of microporous micro-capillary films for the chromatographic purification of biomolecules." Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/289020.
Full textAbstract:
Microporous walled micro-capillary films (MMCFs) are porous polymer films with embedded capillaries. MMCFs have been found to be suitable low-cost chromatography substrates capable of tolerating high flowrates, which suggested they might be a solution to the growing bottleneck in the downstream purification of biopharmaceuticals. However, MMCFs have been mainly tested for binary separations of model proteins and broader capabilities of this technology remain largely unknown. The experimental work presented in this thesis focused on developing MMCFs functionalised with different ligands and their subsequent testing as chromatography media for bioseparations. MMCFs were functionalised to form weak anion (MMCF-DEAE) and weak cation-exchangers (MMCF-gCM and MMCF-CA). Emphasis was placed on low-cost functionalisation methods amenable to single-use applications. To confirm the addition of functional groups on the membranes, a comprehensive characterisation routine was implemented. This included the use of spectroscopy, electron microscopy, elemental analysis and pH titration. The binding performance of these weak ion-exchangers was further assessed by static and dynamic adsorption of model proteins. Next, the functionalised MMCFs were tested for bioseparations with binary and complex mixtures, the latter being more relevant for industrial applications. It was found that MMCFs could selectively separate similarly charged biomolecules using optimised elution strategies. Further, it was observed that MMCF-gCM could capture lysozyme from chicken egg white at a near twenty-fold purity increase compared to the feed. Similarly, this weak cation-exchanger could recover antibodies from unfiltered mammalian cell lysate. The recovered biomolecules were then injected onto MMCF-DEAE to remove nucleic acid impurities in subtractive chromatography mode. Finally, MMCFs were explored for the first time as affinity chromatography supports. Bovine serum albumin (BSA) and Protein A were covalently coupled to the substrate and tested for the capture of relevant analytes. Indeed, it was found that MMCF-BSA could bind bilirubin and MMCF-ProtA could be used to recover antibodies. Given the high cost of Protein A, a cheaper synthetic ligand was coupled onto MMCFs and observed to successfully bind antibodies. Overall, this work has furthered the applications of MMCFs for bioseparations, demonstrating their great versatility and robustness. Furthermore, it opened the field for affinity-based MMCFs, which could have numerous applications in both research and industry. Extensive characterisation methods presented here will greatly simplify future studies with these membranes. While the binding capacity of the developed ion-exchangers was typically two orders of magnitude higher than non-porous MCFs (NMCFs), the low yield achieved with MMCFs currently precludes them from commercial applications. However, optimisation of MMCFs, as outlined in the future work, could make this support more commercially viable and leverage the numerous advantages offered by its unique geometry.
25
Chokazinga, Davlin. "Coordination studies of inositols with aluminium and related cations." Curtin University of Technology, School of Applied Chemistry, 2003. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=14424.
Full textAbstract:
In this work cis-inositol, epi-inositol and myo-inositol carbonate were successfully synthesised and used for coordination studies. The preparation of cis-inositol was achieved by reduction of tetrahydroxybenzoquinone via hydrogenation with palladium hydroxide as the catalyst and was purified by chromatographic separation using Dowex resin. The synthesis of epi-inositol was achieved by the nitric acid oxidation of myo-inositol to form epi-inosose which was subsequently reduced by hydrogenation using palladium hydroxide as the catalyst. myo-Inositol was converted into its mono-orthoformate derivative and the equatorial hydroxy group was then protected as a tertiary-butyldimethylsilyl ether. The carbonate group was introduced onto this protected inositol and then the protecting groups were removed by acid hydrolysis. The coordination characteristics of four inositols, viz cis-inositol, epi-inositol, myo-inositol and myo-inositol carbonate with calcium, aluminium, gallium, lanthanum and samarium ions have been investigated. Interactions of the aluminate anion with epi-inositol and myo-inositol in deuterated sodium hydroxide were also investigated. Three methods were used in the study of complexation behaviour of these systems. namely, [superscript]13C NMR spectroscopy, HPLC and ion exchange chromatography. [superscript]13C NMR spectroscopy was found to be most useful for determining possible complexation behaviour of the inositols. Chemical shift changes of the resonance signals in the [superscript]13C NMR spectra on sequential addition of cations to solutions of the inositols at near neutral pH, have led to determination of possible coordination sites of the inositols. In general, large induced chemical shift changes have been interpreted to signify strong cation-inositol interaction at specific hydroxy groups.Triaxial sites of the inositols have shown a preference to coordinate small ions with ionic size of at least 60 pin, smaller ions than this displayed very weak interactions. Likewise large ions (90-100 pm) imparted weak interactions on triaxial sites of the inositols. These large ions coordinated well with the axial-equatorial-axial sites of the inositols although it was observed that calcium ions appeared to form a 2:1 ligand:cation complex with cis-inositol at the triaxial site despite being a large cation (100 pm). The detection of complex formation by HPLC showed a possible formation of very stable complexes of epi-inositol complexes with calcium ions. However, a change of refractive index of the solution on sequential addition of the cation may have caused an interference in the results such that direct interpretation was not possible. Ion exchange chromatography provided the quickest guide on how strongly the inositols interact with a particular cation. However, determination of complex stoichiometry and or structure was not possible using this technique.
26
Mabakane, Elizabeth Nontombi. "The determination of distribution coefficient for some elements on the macroporous cation exchanger Amberlyst 15 using nitric acid – methanol mixtures." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2329.
Full textAbstract:
Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2016.The main purpose of this study is to understand the application of ion exchange chromatography on separation of charged ions of elements. Ion exchange chromatography is an analytical method, which is used for the separation of elements, quantitation and qualitation. The use of Amberlyst 15 resin as a source of separation for metal ions has been investigated and studies in various academic disciplines such as chemistry and material science. In this research study, Amberlyst 15 resin was investigated in order to understand the separation of positively charged divalent elements ions (Zn2+, Cu2+, Co2+ and Ni2+). The use of nitric acid and methanol mixture enhanced separation of these metal ions by ensuring that nitric acid is constant and varying methanol concentration. In this study, it was found that the resin has a high affinity for the metal ions at high methanol concentration, hence the distribution coefficient values increase but decreases at low methanol concentrations. The complexities of molecular structure of the salts of the elements provide the more understanding of the metal ion interaction with the resin particle. Furthermore, the role and strength of nitric acid to break the structural bonds and release the metal ions to get sorbed on the resin remains the most essential factor of understanding distribution coefficient values. Method validation parameters such as linearity, precision and accuracy of the method were determined. The method precision and accuracy were determined from the QC samples which is expressed as relative error (%RE) with the total coefficient of variation (%CV’s) were < 20%.
27
Motalane, Mpempe Paulus. "Analytical determination of fluorides in South African chemical gypsum." Thesis, Access to E-Thesis, 2004. http://upetd.up.ac.za/thesis/available/etd-04302005-100153/.
Full text
28
Pathange, Lakshmi Prasad. "Characterization of protein microstructure by various chromatographic techniques." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/26851.
Full textAbstract:
Due to the rising health care costs and with the advent of biogenerics, there is a growing demand to develop new and reliable techniques to characterize proteins and biopharmaceuticals. In addition, characterization aids in understanding the intricate relationship between a protein's structure and its function. To address this challenge, two protein structural parameters, 1) amino acid surface area and 2) amino acid microstructure, were chosen to be investigated. Two chromatographic techniques, 1) ion exchange chromatography (IEC) and 2) immobilized metal affinity chromatography (IMAC), were used to characterize the above-mentioned protein structure parameters.
The model protein chosen for our work is T4 lysozyme. The protein consists of 164 amino acids with molecular weight ~ 18 kD. SYBYL 7.1 software was used to generate in silico point mutants. Two categories of protein variants (point mutants) were generated using site-directed protein mutagenesis. The goal for generating point mutants was to obtain mutants that vary in the two structural parameters. The first category point mutants vary in the surface accessibility of a surface accessible histidine residue. The second category point mutants predominantly vary in protein net charge and the amino acid microstructure. In total, seventeen point mutants were generated: 1) category I consists of seven variants that vary predominantly in their histidine surface accessibility, and were obtained by replacing a charged amino acid residue at different locations on the surface of the protein molecule, and 2) category II consists of ten variants that vary in both net charge and charge distribution were obtained by replacing charged and neutral amino acid residues at different locations (different microenvironments) on the protein surface.
PCR technique was used to generate the point mutants. Gene and protein sequencing were employed to confirm the veracity of point mutation. CD and Lysozyme activity assays were performed to determine whether or not the 3D structure of all the protein variants was intact. Zonal analysis was used to obtain the binding strength values of all seventeen variants in IMAC with copper as the immobilized metal ions, and gradient elution method was used to obtain the relative retention times (rRT) values of all the variants in IEC.
The seven lysozyme variants generated in category I each contains one surface histidine residue. In IMAC, there is a correlation between the surface accessibility of the lone surface histidine and the protein's binding strength with R²⁺= 0.76. In IEC, the correlation between the protein's microstructure, which predominantly consists the surface accessibility of the histidine residue, and the protein's retention times was R²⁺= 0.95. However, there were few outlier variants (e.g. variant K83H) which did not follow the correlations. The variations presented by few outlier variants can be attributed to the presence of intramolecular bonds, which restrict the mobility of the amino acid side chains and subsequently hinder the specific interaction between the amino acid residue and chromatographic media.
For category II variants, short and medium range charge perturbations around the sole histidine residue in T4 lysozyme were engineered within 15 Ã distance of histidine. There was a strong correlation (R²⁺ = 0.96) between the theoretical (DeltaDeltaGElec) values, calculated using simple Coulomb's law, and the experimental (DeltaDeltaGB) values, which were obtained by measuring the protein binding strength values using IMAC. Similar correlation (R²⁺= 0.93) was obtained between the change in net charge (-2 to +2 units) and the relative retention times in IEC. Similarly, there were few variants (e.g. S136K, R76D) that did not follow the trends. The deviations of the few outlier variants can be attributed to the presence of unique microstructure effects around the histidine residue. These microstructure effects were quantified in IMAC as (DeltaDeltaGMicro), and in IEC they were quantified by the change in rRT values.
In summary, all seventeen variants had different binding strengths and rRT values indicating the variation in the protein structure around the histidine residue. Our work reveals that it is possible to capture the microstructural effects of a protein through the combination of protein molecular modeling and simple chromatographic experiments.Ph. D.
29
Sines, Brian James. "Evaluation of Phenomena that Determine the Performance of Immunoaffinity, Peptide-Based and Ion Exchange Affinity Sorbents." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/29841.
Full textAbstract:
Insufficient supply and pathogen safety concerns regarding plasma-derived therapeutic proteins, such as fibrinogen and immunoglobulins, have been the impetus for the development of genetic engineering techniques and separations methods for the economical and safe production of these proteins. This study is concerned with the isolation of these important therapeutics from complex media. Immunoaffinity chromatography has been an important method in the isolation of these products, typically being implemented as the final cleanup step yielding an extremely pure, homogenous final product. However, the use of immunoaffinity chromatography in large-scale purification processes have been precluded due to high capital costs and the inherent lability of immunosorbents. Peptide-based affinity sorbents are being developed in order to surmount the inherent limitations posed by monoclonal antibodies that are used as ligands in immunosorbents.
The objective of this research is to quantitatively assess the impact of affinity ligand orientation, local density and transport phenomena on peptide-based affnity sorbent performance. The peptides under study herein can form high-affinity complexes with their protein targets, thus these ligands are one of the newest technologies arising from combinatorial chemistry with applications to the difficult problem of purifying high-molecular weight proteins from complex mixtures. Two types of structural motifs which are common to small peptide affinity ligands derived from combinatorial chemistry are studied here: a linear peptide which is comprised of the affinity recognition sequence in its entirety and a chain structure which displays multiple branches of the recognition sequence emanating from a central lysinic core structure. Two recognition sequences are studied here which bind plasma proteins. One peptide recognition sequence forms a high affinity complex with fibrinogen. Another peptide recognition sequence binds the Fc region of immunoglobulins. Immunglobulins are plasma proteins which range in molecular weight from 155 to 900-kDa and are valuable for therapeutic uses for imparting passive immunity.
This study seeks to identify factors analogous to those manifested in immunosorbent performance that may also be important in the optimal design of peptide-based affinity sorbents. In general, previous research with the design of immunosorbents have found that immunosorbent performance, i.e., target-binding efficiency or activity, is substantially dependent upon several factors which include effects associated with ligand orientation, and local density as related to steric incumbrance of target binding sites, and transport phenomena as related to under utilization of intra matrix volume. In summary, this study asks the questions: (1) What factors regarding ligand orientation, local ligand density, and intraparticle transport phenomena, are important in the optimal design of peptide affinity sorbents?; and (2) Are these effects analogous to those manifested in immunosorbent performance?
This study seeks to investigate the use of techniques used to mitigate the effects associated with these negative factors upon immunosorbent performance in order to elucidate the nature of these same effects upon peptide-based affinity sorbents. For example, oriented ligand immobilization can be facilitated through selective coupling chemistries and the premasking of ligand binding domains prior to immobilization. In addition, the manipulation of local ligand density using novel spatially controlled matrix activation and ligand immobilization methods can be assessed and implemented for the optimization of the performance and design of peptide-based affinity sorbents. This study has found that enhanced transport phenomena into the matrix interior volume can be achieved by using low solids content cellulose matrices having a low extent of crosslinking. This study demonstrates the effective use of these large-particle diameter, low-solids content cellulose hydrogel matrices in immunoaffinity, peptide-based affinity and ion exchange chromatography in the separation of high-molecular weight therapeutic proteins.Ph. D.
This report presents an evaluation of the design of low-solids content, large-particle diameter beaded cellulose supports for column-mode protein purification. The study presented here optimizes the molecular accessibility of the cellulose support to high molecular weight proteins relative to the mechanical stability of the support at high operating linear velocities by the manipulation of bead particle diameter and solids content. A novel epoxidegradient activation method (epoxy-GAM) is developed for creating a gradient of support activation for support crosslinking and affinity ligand installation in the preparation of DEAE hydrogel matrices. These cellulose hydrogel supports were evaluated with regards to structure, dynamic and static binding capacity, pressure-flow stability, chemical stability and intraparticle transport phenomena. The utility of the low-solids content, large-particle diameter DEAE hydrogel matrices was demonstrated in a column-mode protein purification using albumin and fibrinogen mixtures.
30
Roman, Henry James. "Ostrich calpastatin purification and partial characterization of the liver inhibitor." Thesis, University of Port Elizabeth, 2000. http://hdl.handle.net/10948/d1015522.
Full textAbstract:
The isolation and purification of calpastatin from ostrich liver is presented, along with its physicochemical and kinetic properties. By using extraction from liver, ion-exchange chromatography on DEAE-Toyopearl, heating to 90 °C for 10 min and rechromatography on Toyopearl Super-Q 650 S, ostrich calpastatin was isolated and purified from ostrich liver. The purified intact calpastatin showed homogeneity on SDS-PAGE (Mr of 105.6 K). Amino acid analysis showed that ostrich calpastatin resembled that of rabbit liver and human erythrocyte calpastatin. An N-terminal sequence could not be obtained because the N-terminus was found to be blocked by an as yet unknown amino acid residue. The Mr values of degradative forms of ostrich liver calpastatin were determined to be 56 K and 90 K. By using PAG-IEF the pI of the intact form was determined to be 5.1. Ostrich liver calpastatin behaved characteristically like other calpastatins during kinetic analysis. Calpastatin inhibited calpain from pH 6 to 9 and was found to be unaffected by temperatures as high as 100 °C. Calpastatin also inhibited calpain activity at Ca2+ concentrations ranging from 1 to 10 mM. The inhibitor was shown to be phosphorylated because after incubation with alkaline phosphatase there was a decrease in inhibitory activity. No inhibitory effects were detected against other proteases such as chymotrypsin and trypsin, with both proteases inactivating calpastatin completely. Ostrich liver calpain was shown to have a pH optimum of 7.5 and a temperature optimum of 30 °C. In terms of its thermodynamic properties it resembled that of other ostrich proteases; DH, DS and DG being 47.07 kJ/mol, -91.1 J/mol/K and 74.237 kJ/mol, respectively. Ostrich liver calpain showed a Km of 0.14 % (w/v). The enzyme was active at both milli- and micro-molar concentrations of Ca2+. Ostrich liver calpastatin showed many physical, chemical and kinetic properties similar to those of other known calpastatins.
31
PIRES, MARIA A. F. "Aplicacao da cromatografia de ions no controle de materiais de interesse nuclear." reponame:Repositório Institucional do IPEN, 1989. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9918.
Full textAbstract:
Made available in DSpace on 2014-10-09T12:32:50Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:08:43Z (GMT). No. of bitstreams: 1 03535.pdf: 3650830 bytes, checksum: bbc8f2898c5bbb98e5ef60f35f76a159 (MD5)
Tese (Doutoramento)
IPEN/T
Instituto de Química - Universidade de São Paulo - IQ/USP
32
Chen, Xin. "Development of Monolithic Stationary phases for Cation-Exchange Capillary Liquid Chromatography of Peptides and Proteins." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2467.
Full textAbstract:
This dissertation focuses on the preparation of polymeric monolithic capillaries for ion exchange chromatography of peptides and proteins, since polymeric monoliths have shown promise for providing improved protein separations. Characteristics of monolithic columns include low back pressure, simplicity of fabrication and biocompatibility. Preparation of strong and weak cation-exchange monolithic stationary phases in 75 μm I.D. capillaries by direct in situ copolymerization was achieved using various functional monomers including sulfopropyl methacrylate, phosphoric acid 2-hydroxyethyl methacrylate, bis[2-(methacryloyloxy)ethyl] phosphate and 2-carboxyethyl acrylate with polyethylene glycol diacrylate and other PEG materials. The resulting monoliths provided excellent ion exchange capillary LC of peptides and proteins with good run-to-run [relative standard deviation (RSD) < 1.99%] and column-to-column (RSD < 5.64%) reproducibilities. Narrow peaks were obtained and peak capacities of over 20 were achieved. Dynamic binding capacities of over 30 mg/mL of column volume for lysozyme were measured. A single monomer was used to synthesize a phosphoric acid containing monolith to improve its stability and reproducibility. The monolith was synthesized from only BMEP in 75 μm I.D. UV transparent fused-silica capillaries by photo-initiated polymerization. A dynamic binding capacity (lysozyme) of approximately 70 mg/mL of column volume was measured. Efficiencies of 52,900 plates/m for peptides and 71,000 plates/m for proteins were obtained under isocratic conditions. Good reproducibilities were achieved. Zwitterionic monolithic columns based on photo-initiated copolymerization of N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl)ammonium betain and poly(ethylene glycol) diacrylate were prepared in 75 μm I.D. fused silica capillaries for hydrophilic interaction chromatography. Inverse size exclusion chromatography was used to characterize the pore structure of the resulting monolith. A typical hydrophilic interaction chromatography mechanism was observed when the organic content in the mobile phase was higher than 60%. Good separations of amides, phenols, and benzoic acids were achieved. The effects of mobile phase pH, salt concentration, and organic modifier content on retention were investigated.
33
Bruce, Ruey K. "Synthesis and purity characterization of high purtiy 3,3ʹ-disulfonated-4,4ʹ-dichlorodiphenyl sulfone (SDCDPS) monomer by ion chromatography." Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1243347553.
Full text
34
MARQUES, MARIA N. "Cromatografia de ions aplicada na especia‡ao de cromio hexavalente em amostras de interesse ambiental." reponame:Repositório Institucional do IPEN, 1999. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10739.
Full textAbstract:
Made available in DSpace on 2014-10-09T12:43:29Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T13:58:25Z (GMT). No. of bitstreams: 1 06497.pdf: 7575269 bytes, checksum: 3551f60999aef01a16217b24b89a7f9b (MD5)
Mestrado (Dissertacao)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
35
Nicolas-Simonnot, Marie-Odile. "Contribution à l'étude de la chromatographie frontale des protéines par échange d'anions : Application à l'albumine du serum bovin bovin." Vandoeuvre-les-Nancy, INPL, 1991. http://docnum.univ-lorraine.fr/public/INPL_T_1991_NICOLAS_SIMONNOT_M_O.pdf.
Full textAbstract:
La chromatographie d'échange d'anions mettant en jeu une protéine fait intervenir simultanément plusieurs phénomènes : l'échange d'ions proprement dit, ainsi que d'autres réactions, essentiellement de dissociation, en phase liquide ou solide. La démarche adoptée ici consiste à découpler toutes les contributions et à les examiner séparément, avant de les regrouper dans un modèle global. On étudie le comportement des supports échangeurs d'ions faibles en fonction de l'environnement ionique, les interactions entre les électrolytes faibles (tampons de pH) et les échangeurs d'anions, les interactions entre la protéine (albumine du sérum de bovin) et la solution (modélisation des courbes de dosage), et les interactions entre la protéine et des échangeurs d'anions (mesures d'isothermes en réacteur ferme et expériences en colonne en milieu tamponné ou non). On propose un modèle de la protéine (au niveau de l'échange d'ions), dont le comportement global s'approche de celui d'un électrolyte faible. Avant d’aborder les expériences en colonne avec une protéine-modèle (albumine de sérum bovin), on analyse les interactions entre cette protéine et la solution (modélisation de courbes de dosage). De même, on étudie les interactions entre la protéine et des échangeurs d’anions par la mesure d’isothermes dans différentes conditions. Enfin, des expériences de chromatographie frontale sont présentées. On commence par des systèmes « simples » du point de vue de l’échange d’ions (échanges binaires ou ternaires, en milieu non tamponné), avant de travailler en milieu tampon (où toutes les contributions sont mêlées). L’interprétation de ces expériences nous conduit à proposer un mécanisme d’échange. On montre que le comportement global de la protéine s’approche de celui d’un électrolyte faible, ce qui constitue un point de départ de vue de l’élaboration d’un modèle
36
Castiblanco, Adriana P. "Expression and Purification of Engineered Calcium Binding Proteins." Digital Archive @ GSU, 2009. http://digitalarchive.gsu.edu/chemistry_theses/20.
Full textAbstract:
Previous studies in Dr. Yang’s laboratory have established a grafting, design, and subdomain approach in order to investigate the properties behind Ca2+-binding sites located in Ca2+-binding proteins by employing engineered proteins. These approaches have not only enabled us to isolate Ca2+-binding sites and obtain their Ca2+-binding affinities, but also to investigate conformational changes and cooperativity effects upon Ca2+ binding. The focus of my thesis pertains to optimizing the expression and purification of engineered proteins with tailored functions. Proteins were expressed in E. coli using different cell strains, vectors, temperatures, and inducer concentrations. After rigorous expression optimization procedures, proteins were further purified using chromatographic and/or refolding techniques. Expression and purification optimization of proteins is essential for further analyses, since the techniques used for these studies require high protein concentrations and purity. Evaluated proteins had yields between 5-70 mg/L and purities of 80-90% as confirmed by SDS-PAGE electrophoresis.
37
Guzmán, Laparra Gabriel Eduardo. "Use of affordable technology for the sensitive and specific diagnosis of onchocerciasis (river blindness) /." Stockholm, 2002. http://diss.kib.ki.se/2002/91-7349-321-x.
Full text
38
Jones, Ward M. "Purification and characterization of s-adenosylmethionine synthetase from candida albicans." Virtual Press, 1989. http://liblink.bsu.edu/uhtbin/catkey/722458.
Full textAbstract:
S-Adenosylmethionine (SAM) synthetases isolated from both the yeast and hyphal-phase of the dimorphic fungus, C. albicans, were partially purified using DEAE cellulose ion-exchange column chromatography. Further characterization was accomplished using enzyme kinetics and specific enzyme effectors. SAM synthetase is the enzyme responsible for synthesis of SAM which is the major methyl group donor in the methylation of macromolecules. Kinetic studies on column samples, from both phases, were performed. The yeast-phase enzyme had apparent Km ranges for L-methionine and ATP of 1.06-1.42mM and 1.11-1.69mM, respectively. The hyphal-phase enzyme had apparent Km ranges for L-methionine and ATP of 1.34-2.66mM and 3.29-6.28mM, respectively. Effector studies (in vitro) indicate that 10% (v/v) dimethyl sulfoxide (DMSO) and 5mM cycloleucine inhibit SAM Synthetase from both phases, 24% and 46%, respectively. The methionine analogues DLmethionine sulfone, DL-methionine-DL-sulfoxide and L-methioninesulfoximine and sinefungin, an analog of SAM, had no effect on SAM synthetase activity. Although the data is inconclusive with respect to the existence of isozymes, the observed Km's of the yeast and hyphal-phases are different suggesting that isozymes may exist. Additionally, the yeast-phase DEAE column profile has a shoulder prior to the main peak of activity indicating that more then one form of the enzyme may be present.Department of Biology
39
OLIVEIRA, INEZ C. de. "Recuperacao e purificacao do uranio utilizado em alvos para a producao de Mosup99." reponame:Repositório Institucional do IPEN, 1998. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10688.
Full textAbstract:
Made available in DSpace on 2014-10-09T12:43:03Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:05:37Z (GMT). No. of bitstreams: 1 06178.pdf: 4301800 bytes, checksum: 8ef60a5fb58c4649ffd7c1a0c70dc421 (MD5)
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
40
Richardson, Ashley E. "Hydrophilic interaction and micellar liquid chromatography approaches for the separation of aromatic carboxylic acid positional isomers plus ion exchange chromatography for the separation of sulfonated compounds." Miami University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=miami1511295591427557.
Full text
41
Monaco, Enzo. "pH Transients in Hydroxyapatite chromatography columns." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
Find full textAbstract:
Ceramic Hydroxyapatite (CHT), with empirical formula (Ca5(PO4)3OH)2, is a material used as ion exchange resin in chromatographic applications. The material, having both positive and negative charged sites, can be used in many different contexts encountered in the protein purification processes. Nevertheless, the resin shows an intrinsic limitation for this kind of applications: even if the material solubility in water is very low at pH values higher than 6.5, it sharply increases in more acidic environments, reducing the life of the material and increasing the operative costs of the process, making problematic the CHT application at these conditions.
There is a further complication related to the CHT application: it is experimentally reported that the result of the resin interactions with salts is a pH transient occurring in the liquid phase of the chromatographic column.
These pH variations are temporary but remarkable, they may influence in an important manner the material solubility, affecting the number of utilization cycle of the fixed bed and, eventually, the stability of the proteins involved in the separation process.
In this work the principal aspects contributing at the selection of the operating pH and of the buffering specie are analyzed, discussing also the effect of the buffer itself on the material solubility.
Then, it is reported a mathematical model useful for the description of the dynamic behavior of the column and it is proposed an interaction mechanism between the salts of the mobile phase and the stationary phase. In particular, it is emphasized the discussion regarding the different affinity shown by the stationary phase for the different counter-ions which may accompanies the buffering specie.
Finally, a series of equations are developed at the scope to obtain a model useful to describe the observed pH transients.
42
Jen, Jen-Fon. "Analysis of Acid Gas Emissions in the Combustion of the Binder Enhanced d-RDF by Ion Chromatography." Thesis, University of North Texas, 1988. https://digital.library.unt.edu/ark:/67531/metadc331848/.
Full textAbstract:
Waste-to-energy has become an attractive alternative to landfills. One concern in this development is the release of pollutants in the combustion process. The binder enhanced d-RDF pellets satisfy the requirements of environmental acceptance, chemical/biological stability, and being storeable. The acid gas emissions of combusting d-RDF pellets with sulfur-rich coal were analyzed by ion chromatography and decreased when d-RDF pellets were utilized. The results imply the possibility of using d-RDF pellets to substitute for sulfur-rich coal as fuel, and also substantiate the effectiveness of a binder, calcium hydroxide, in decreasing emissions of SOx.
In order to perform the analysis of the combustion sample, sampling and sample pretreatment methods prior to the IC analysis and the first derivative detection mode in IC are investigated as well. At least two trapping reagents are necessary for collecting acid gases: one for hydrogen halides, and the other for NOx and SOx. Factors affecting the absorption of acid gases are studied, and the strength of an oxidizing agent is the main factor affecting the collection of NOx and SOx. The absorption preference series of acid gases are determined and the absorption models of acid gases in trapping reagents are derived from the analytical results. To prevent the back-flushing of trapping reagents between impingers when leak-checking, a design for the sampling train is suggested, which can be adopted in sample collections. Several reducing agents are studied for pretreating the sample collected in alkali-permanganate media. Besides the recommendation of the hydrogen peroxide solution in EPA method, methanol and formic acid are worth considering as alternate reducing agents in the pretreatment of alkaline-permanganate media prior to IC analysis. The first derivative conductivity detection mode is developed and used in IC system. It is efficient for the detection and quantification of overlapping peaks as well as being applicable for non-overlapping peaks.
43
SANTOS, ELIANE E. dos. "Estudo da separacao de galio e zinco por meio de resinas trocadoras e de adsorcao de ions. Obtencao de sup67Ga para uso em medicina nuclear." reponame:Repositório Institucional do IPEN, 1995. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10426.
Full textAbstract:
Made available in DSpace on 2014-10-09T12:38:34Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:05:19Z (GMT). No. of bitstreams: 1 06051.pdf: 3741184 bytes, checksum: a75ec12829b661a213233009e5987d2a (MD5)
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
44
OLIVEIRA, JOAO E. de. "Influência do hospedeiro (CHO) e da estratégia de cultivo nas estruturas glicídicas e propriedades moleculares da tireotrofina humana." reponame:Repositório Institucional do IPEN, 2007. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11590.
Full textAbstract:
Made available in DSpace on 2014-10-09T12:53:36Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:08:07Z (GMT). No. of bitstreams: 0
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
45
Sousa, Anayla dos Santos. "Estudo dos modos batelada e reciclo externo estacionário para a separação do ácido hialurônico por cromatografia de exclusão por tamanho." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266865.
Full textAbstract:
Orientador: Cesar Costapinto SantanaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
Made available in DSpace on 2018-08-19T00:34:49Z (GMT). No. of bitstreams: 1 Sousa_AnayladosSantos_D.pdf: 1255579 bytes, checksum: 2c0a223e27891ba584d4f621ffa8e2bd (MD5) Previous issue date: 2011
Resumo: O Ácido hialurônico (AH) é um polissacarídeo linear com importantes aplicações na indústria farmacêutica, médica e cosmética, fazendo-se necessária sua purificação por ser oriundo de uma variedade de fontes, animal e não animal. Assim sendo, o presente trabalho discorre sobre a separação do AH produzido por fermentação em meio de cultura sintético, utilizando a técnica cromatográfica de exclusão por tamanho. Determinaram-se as melhores condições de separação utilizando, inicialmente, uma coluna de exclusão por tamanho operando em batelada. Estas condições foram mantidas em todos os ensaios e serviram de modelo para a obtenção dos parâmetros para o escalonamento do processo. Ainda em batelada, avaliou-se a inserção da técnica cromatográfica de troca iônica acoplada à exclusão por tamanho, com o intuito de aprimorar a separação do AH, averiguando resinas de caráter catiônico e aniônico. Realizou-se um estudo comparativo entre o processo em batelada, com e sem a inserção da troca iônica, e o semicontínuo operado com reciclo externo estacionário (REE), visando a obtenção de frações de AH e proteínas com elevado grau de pureza. Considerando-se o processo semicontínuo operado em REE foram avaliados diferentes volumes de reciclo, sendo eles 1,0; 1,5; 2,25 e 3,0 mL. Os resultados obtidos com o processo semicontínuo em REE alcançaram um percentual de purificação entre 92% e 97% para o AH, trabalhando-se com volumes de reciclo de 1,0 a 3,0 mL, enquanto que para as proteínas mostrou-se inviável. A inserção da cromatografia de troca iônica mostrou-se promissora com o uso da resina catiônica, apresentando 98% de pureza com um rendimento de 99% para o AH; ao contrário da resina aniônica que exibiu uma perda mássica de AH em torno de 50%. O escalonamento do processo cromatográfico de exclusão por tamanho mostrou-se possível, apresentando resultados semelhantes à operação em batelada
Abstract: The hyaluronic acid (HA) is a linear polysaccharide with important applications in the pharmaceutical, medical and cosmetics industry. Its purification is necessary because it is in a mixture coming from a variety of sources, animal and non-animal. The aim of this work is the separation of HA obtained by fermentation in synthetic medium, using the technique of size exclusion chromatography. The best conditions for HA separation were determined using, initially, a batch operation size exclusion column. These conditions were maintained in all trials and served to obtain the parameters for the large scale process. The batch operation also evaluated the ion exchange chromatography technique coupled to size exclusion, in order to enhance the separation of HA by examining cationic and anionic resins. A comparative study was carried out between the batch process, with and without the inclusion of ion exchange, and the semi-batch process with steady state recycling (SSR), in order to obtain fractions of HA and proteins with high purity. The semi-batch process operated with SSR assessed in differents volumes of recycle (1.0, 1.5, 2.25 and 3.0 mL). The results obtained with the semi-batch process with SSR achieved a purification percentage between 92 % and 97% for HA, working with recycle volumes from 1.0 to 3.0 mL, showing to be feasible for HA, while for the proteins proved to be unfeasible, with a maximum of 60 % purity. The ion-exchange chromatography obtained good results with the use of cationic resin, with 98% of purity and a yield of 99 % for HA, unlike the anionic resin which exhibited a mass loss of HA around 50 %. The scale-up process for size exclusion chromatography proved to be possible, with similar results to batch operation
Doutorado
Desenvolvimento de Processos Biotecnologicos
Doutor em Engenharia Química
46
OLIVEIRA, JOAO E. de. "Purificacao de hormonio de crescimento humano recombinante obtido no espaco periplasmico de ESCHERICHIA COLI, visando sua aplicacao clinica." reponame:Repositório Institucional do IPEN, 1999. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10755.
Full textAbstract:
Made available in DSpace on 2014-10-09T12:43:39Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:09:47Z (GMT). No. of bitstreams: 1 06652.pdf: 3582362 bytes, checksum: acb423f59896fb445118557871bc22b3 (MD5)
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
47
Van, der Meulen N. P. (Nicolas Philip). "The cyclotron production of selected radionuclides using medium energy protons." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/21914.
Full textAbstract:
Thesis (PhD)--Stellenbosch University, 2008.ENGLISH ABSTRACT: Radiochemical research involving ion exchange chromatography is of paramount importance to the future of radionuclide production at the Radionuclide Production Group (RPG) of iThemba LABS. It is required for the production of high-activity yields of radionuclides to effectively remove impurities and for the safety of the operators performing such productions. The radiochemical separations of some new products from their target material, as well as experiments to determine whether production is viable, are described. 67Ga is currently being produced at the RPG and makes use of zinc targets. With the production of ultra-pure 67Ga, it was necessary to remove any Fe(III) impurities from the final product, such that it may be possible to label peptides with this product. The use of Amberchrom CG161M for this purpose was found to be satisfactory. Interest was shown in 88Y by an overseas company for the manufacture of sources. While a method involving extraction of the radionuclide and the ion exchange thereof using Chelex 100 chelating resin had been published, problems with the production persisted. Three methods, using ion exchange chromatography, were devised to produce the radionuclide, with two of them being adopted for production purposes. Thick-target nuclear data have also recently been accumulated in collaboration with colleagues from ATOMKI, Debrecen, Hungary. There is a large demand for 82Sr for the manufacture of 82Sr/82Rb generators for medical use. A method was developed to manufacture this radionuclide with thicker (32 g) target material, bombarded in the Vertical Beam Target Station (VBTS), and to separate 82Sr from its target material with the use of Purolite S950 chelating resin. 68Ge/68Ga generators are becoming increasingly important in the world of radiopharmaceuticals. A project to develop a local generator was funded by the Innovation Fund and research was performed to produce 68Ge, such that the generator could be manufactured. This involved bombarding thicker Ga targets in the VBTS and performing the chemical separation using AG MP-1 anion exchange resin. The final product was loaded onto generators, although tests performed on different materials to the ones being marketed are also reported in this work. A project was initiated to study the cluster radioactive decay of 223Ac via 14C and 15N emission. To produce 223Ac for these observations, a Th target was bombarded. The 227Pa was separated from the target material using AG MP-1 macroporous anion exchange resin and used as a source, which decayed to 223Ac. The chemical separation and the drying of the final product onto a source plate were completed within approximately 70 minutes from the end of bombardment. The work was performed in collaboration with JINR, Russia, and University of Milan and INFN, Italy. 133Ba has a half-life of over 10 years and is an expensive radionuclide to produce. It has been used in medical and biological studies and there still appears to be a demand for it. A method was devised, utilizing AG50W-X4 cation exchange resin, to separate 133Ba from its CsCl target material. Agricultural specialists in the past have shown an interest in 28Mg, to determine the uptake of the element in fruit. It has long been regarded by some of the local researchers as an interesting project to investigate. It has been determined that the product can be produced in reasonable quantities using LiCl target material, with ten targets being bombarded in series using a 200 MeV proton beam delivered by the Separated Sector Cyclotron. A method, involving the use of Purolite S950 chelating resin, was devised to separate 28Mg from its target material.
AFRIKAANSE OPSOMMING: Radiochemiese navorsing, wat ioonuitruiling chromatografie behels, is van uiterste belang vir die toekoms van die produksie van radionukliede by die Radionukliedproduksiegroep (RPG) van iThemba LABS. Dit is nodig vir die hoë aktiwiteit opbrengs van radionuklied produkte om onsuiwerhede te verwyder en vir die veiligheid van die operateurs wat die produksies moet uitvoer. Die skeiding van nuwe produkte van hulle skyfmateriaal, sowel as eksperimente om vas te stel of ‘n produksie uitvoerbaar is, word in die werk beskryf. 67Ga word tans by RPG vervaardig en maak gebruik van sink as skyfmateriaal. Vir die produksie van “ultra-suiwer” 67Ga was dit belangrik om enige Fe(III) onsuiwerhede uit die finale produk te verwyder om sodoende peptiede merking te kan uitvoer. Die gebruik van Amberchrom CG161M hars was voldoende vir dié eksperiment. ‘n Oorsese maatskappy het belangstelling getoon in 88Y vir die vervaardiging van bronne. Alhoewel ‘n metode wat die ekstraksie van die radionuklied en die ioonuitruiling daarvan met die gebruik van Chelex 100 chelerende hars reeds gepubliseer was, het probleme met die produksie voortgeduur. Drie metodes is opgestel om 88Y te produseer, waarvan twee van die metodes tans gebruik word vir produksie doeleindes. Dik-skyf kerndata is ook versamel in samewerking met kollegas van ATOMKI, Debrecen, Hongarye. Daar is ‘n groot aanvraag vir 82Sr vir die vervaardiging van 82Sr/82Rb generators vir mediese doeleindes. ‘n Metode is ontwikkel om die radionuklied te vervaardig van dikker skyfmateriaal (32 g), in die Vertikale Bundelstasie gebombardeer, en om 82Sr van sy skyfmateriaal te skei met die gebruik van Purolite S950 chelerende hars. 68Ge/68Ga generators is besig om toenemend belangrik te word in die wêreld van radiofarmasie. iThemba LABS kry baie navrae om die produk te vervaardig. Die projek was ook deel van die voorlegging aan die “Innovation Fund” en ‘n manier is ondersoek om 68Ge te vervaardig, wat benodig word om so ‘n generator te laai. Dik Ga skyfmateriaal word in die Vertikale Bundelstasie gebombardeer en ‘n chemiese skeiding is uitgevoer deur gebruik te maak van AG MP-1 anioonuitruiling hars. Die finale produk is op die generators gelaai vir toetsdoeleindes. Toetse is ook op ‘n ander tipe generator uitgevoer en word in die werk beskryf. ‘n Projek is begin om “cluster” radioaktiewe verval van 223Ac, via 14C en 15N emissie, te bestudeer. ‘n Th-skyf is met protone gebombardeer om die 223Ac te produseer vir die eksperiment. 227Pa is vervaardig en geskei van die skyfmateriaal. Dit is gedoen met die gebruik van AG MP-1 makroporeuse anioonuitruiling hars en drooggemaak op ‘n bronplaat, waar dit verval het na 223Ac. Die chemiese skeiding en die droogmaak van die finale produk op ‘n bronplaat is uitgevoer binne 70 minute na Einde van Bombardering (EVB). Die werk is deel van ‘n samewerking met kollegas van JINR, Rusland, en die Universiteit van Milaan, sowel as INFN, Italië. 133Ba het ‘n halveertyd van oor die tien jaar en is ‘n duur produk om te vervaardig. Dit is al gebruik in mediese en biologiese studies en daar is deesdae ‘n redelike aanvraag daarvoor. ‘n Metode is uitgewerk om 133Ba te skei van die CsCl skyfmateriaal met die gebruik van AG50W-X4 katioonuitruiling hars. Spesialiste in landboustudies het in die verlede belangstelling getoon in 28Mg. Dit word gebruik om die absorpsie van dié element in vrugte te ondersoek. Die produk kan vervaardig word met die gebruik van LiCl skyfmateriaal: tot soveel as tien skywe (agter mekaar) word gebombardeer met ‘n 200 MeV protonbundel te iThemba LABS. ‘n Metode, wat Purolite S950 behels, is daargestel om 28Mg van die skyfmateriaal te skei.
48
Dias, Jailson Cardoso. "Determinação de acetato, nitrato, ferro(II), ferro(III) e cobre em etanol combustivel por cromatografia de ions." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/248380.
Full textAbstract:
Orientador: Lauro Tatsuo KubotaTese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
Made available in DSpace on 2018-08-15T10:20:51Z (GMT). No. of bitstreams: 1 Dias_JailsonCardoso_D.pdf: 1120921 bytes, checksum: 080b276b57f19a203109def137925235 (MD5) Previous issue date: 2010
Resumo: O contexto geral deste trabalho se insere na área de desenvolvimento de métodos analíticos para a separação cromatográfica e detecção de íons em biocombustíveis. Diversos procedimentos de otimização (uni e multivariada) foram executados inicialmente visando estabelecer as melhores condições para uma separação eficiente e seletiva dos diferentes analitos. Posteriormente, os principais parâmetros analíticos foram investigados a fim de avaliar o desempenho e a aplicabilidade de cada método pré-estabelecido. Ao todo, três metodologias foram otimizadas, validadas e aplicadas para a análise de bioetanol, sendo a primeira para a determinação dos íons acetato e nitrato e as demais para a determinação dos íons ferro(II), ferro(III) e cobre (sistemas de eluição a base dos ácidos dipicolínico e quelidâmico). As técnicas de cromatografia líquida por troca iônica com detecção condutimétrica (CLTI-DC) e cromatografia líquida por quelação de íons com detecção fotométrica (CLQI-DF) foram utilizadas para os compostos aniônicos e os íons metálicos, respectivamente. De maneira geral, os resultados obtidos evidenciaram o desempenho analítico satisfatório para os três métodos desenvolvidos. Com exceção do ferro(II), todos os demais analitos apresentaram baixos níveis de detectabilidade, da ordem de mg L. Finalmente, diversas amostras de álcool etílico hidratado combustivel (AEHC) foram analisadas diretamente, sem a necessidade de pré-tratamento, para demonstrar a aplicabilidade de cada método
Abstract: The overall context of this work is in the area of development of analytical methods for the chromatographic separation and detection of ions in biofuels. Several optimization procedures (uni- and multivariate) were performed initially in order to establish the best conditions for an efficient and selective separation of different analytes. Subsequently, the main analytical parameters were investigated to assess the performance and applicability of each method. In all, three methods were optimized, validated and applied to the analysis of fuel ethanol, the first being for the determination of nitrate and acetate and the others for the determination of iron(II), iron(III) and copper (eluents based on dipicolinic and chelidamic acids). The techniques of high performance ion-exchange chromatography with conductivity detection (HPIEC-CD) and high performance chelation ion chromatography with photometric detection (HPCIC-PD) were used for the anionic compounds and metal ions, respectively. Overall, the results showed good analytical performance for the three methods developed. With the exception of the iron(II), all other analytes were detected at mg L levels. Finally, several samples of hydrated fuel ethanol were analyzed with no pretreatment to demonstrate the applicability of each method
Doutorado
Quimica Analitica
Doutor em Ciências
49
Oliveira, Thais de. "Recuperação e reciclagem dos ácidos nítrico e sulfúrico e do Molibdênio dos resíduos líquidos das indústrias de lâmpadas." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-26092011-150525/.
Full textAbstract:
O tratamento de rejeitos de determinados processos industriais vem ganhando importância, seja pelo impacto negativo do simples descarte no meio ambiente, seja pelo valor econômico de materiais e substâncias que podem ser eventualmente recuperados e reciclados. O rápido empobrecimento de reservas minerais primárias e o aumento de demanda de energia são problemas que merecem atenção especial. Neste contexto, a recuperação de metais existentes nos rejeitos de alguns processos de fabricação assume papel de maior importância. A recuperação do molibdênio presente em soluções nitro-sulfúricas, na forma de rejeitos líquidos do processo de fabricação de lâmpadas incandescentes e fluorescentes, não constitui exceção no que diz respeito à importância da reciclagem. Este rejeito, proveniente da dissolução dos mandris de conformação dos filamentos de tungstênio das lâmpadas, apresenta valores que podem ser recuperados e até reciclados no próprio processo. É o caso dos ácidos nítrico e sulfúrico. Já o molibdênio, presente em concentrações em torno de 40 a 90 g.L-1, pode ser recuperado e utilizado na fabricação de aços especiais, pigmentos, lubrificantes, adubo, etc. Neste trabalho foram desenvolvidos dois processos de recuperação deste rejeito. No primeiro, o rejeito é diluído e por cromatografia de troca iônica o molibdênio é recuperado. Os ácidos efluentes são destilados para a retirada da água. No segundo processo, o rejeito passa por uma destilação e ao mesmo tempo o molibdênio é precipitado. Em ambos os processos, os ácidos recuperados podem voltar à fábrica de lâmpadas para a dissolução dos mandris do filamento de tungstênio e o molibdênio encontra outras diferentes aplicações, além de possuir um valor significativo no mercado.The waste treatment of certain industrial processes is becoming more important, either by the economic impact of simple disposal in the environment, or by the economic value of materials and substances that can eventually be recovered and recycled. The rapid depletion of mineral reserves and increasing primary energy demand are problems that deserve special attention. In this context, the recovery of metals present in waste of some manufacturing processes assumes a great importance. The recovery of molybdenum present in nitro-sulfur solutions in the form of liquid waste in the manufacturing process of incandescent and fluorescent lamps, is no exception with regard to the importance of recycling. The tailing from the dissolution of the molybdenum mandrel wires used in the conformation of the tungsten filament of electric lamps, has values that can be recovered and recycled to the process itself. Is the case of sulfuric and nitric acids. Molybdenum, present in concentrations around 40 to 90 g.L-1, can be recovered and used in the manufacture of special stainless steel, pigments, lubricants, fertilizer, etc.. In this work two processes for the recovery of this waste were proposed. At the first one, the waste is diluted and molybdenum is recovered by ion-exchange chromatography. The effluent acid from this process was distilled to extract water used in the dilution step. In the second case, the waste goes through a distillation while the molybdenum is precipitated. In both cases, the acids are recovered back to the lamp factory for the dissolution of the molybdenum mandrel wires and molybdenum finds other different applications, as well as having significant value in the market.
50
CAMARGO, IARA M. C. de. "Determinacao da concentracao dos isotopos naturais de uranio e torio em amostras de agua." reponame:Repositório Institucional do IPEN, 1994. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10405.
Full textAbstract:
Made available in DSpace on 2014-10-09T12:38:19Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:04:41Z (GMT). No. of bitstreams: 1 05677.pdf: 3521641 bytes, checksum: 4f8e0c1a38cebeb07dd9281a01683f8e (MD5)
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP