Separation, preconcentration and determination of rare earth elements by inductively coupled plasma emission spectroscopy

 

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dc.contributor.advisor Orren, Michael J en_ZA
dc.contributor.author Cracknell, R H en_ZA
dc.date.accessioned 2017-01-26T07:05:53Z
dc.date.available 2017-01-26T07:05:53Z
dc.date.issued 1988 en_ZA
dc.identifier.citation Cracknell, R. 1988. Separation, preconcentration and determination of rare earth elements by inductively coupled plasma emission spectroscopy. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/23192
dc.description.abstract Rare earth elements, (REE), at ug g⁻¹ levels are used for studies of petrogenisis of different geological materials. For these studies, the REE must be determined precisely. An analytical program was established using an IL 200 Inductively Coupled Plasma, (ICP), spectrometer for the determination of the REE in various matrices, taking into consideration both matrix and spectral interferences, which were found to be severe in some cases. Dissolution of the sample, (0.4-1.0 g), was carried out using two methods; a microwave heated dissolution using a modified commercial microwave oven and a conventional oven heated closed pressure digestion vessel method. The results of these two methods were compared to determine the viability of using the more rapid microwave heated method. Separation of the REE from matrix elements was investigated using three cation exchange resins; Amber lite IR 120 (H), Zeocarb 225 and Dowex 50-WXS. A gradient acid elution method was established using a 15 cm by 20 mm Zeocarb 225 column. The sample was eluted with 140 ml of a 1.5 M H⁺ solution containing 0.75 M Cl⁻ and 0.75 M NO₃⁻, this fraction containing all the matrix elements. The REE were then eluted from the resin with 100 ml of 3 M HNO₃. The REE containing fraction was then reduced to 5 ml, diluted to 10 ml, and analysed for REE content. Liquid-liquid extraction methods for the separation of REE from matrix elements were investigated. It was found that the REE could be extracted synergistically from various buffered aqueous acidic media into chloroform, (CHCl₃), by hexafluoroacetylacetone, (HHFA), and quinoline. Acetylacetone, ( AcAc), was found to react with hexamethylenetetramine, (hexamine), when hexamine was used to buffer the aqueous phase during extraction procedures. The product of this reaction, 3.5-diacetyl-1.4-dihydro-2.6-dimethyl pyridine, was identified using X-ray crystallography. en_ZA
dc.language.iso eng en_ZA
dc.subject.other Earths, Rare~Plasma spectroscopy en_ZA
dc.title Separation, preconcentration and determination of rare earth elements by inductively coupled plasma emission spectroscopy en_ZA
dc.type Master Thesis
dc.date.updated 2016-11-22T09:17:05Z
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Science en_ZA
dc.publisher.department Department of Physics en_ZA
dc.type.qualificationlevel Masters
dc.type.qualificationname MSc en_ZA
dc.identifier.apacitation Cracknell, R. H. (1988). <i>Separation, preconcentration and determination of rare earth elements by inductively coupled plasma emission spectroscopy</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Physics. Retrieved from http://hdl.handle.net/11427/23192 en_ZA
dc.identifier.chicagocitation Cracknell, R H. <i>"Separation, preconcentration and determination of rare earth elements by inductively coupled plasma emission spectroscopy."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Physics, 1988. http://hdl.handle.net/11427/23192 en_ZA
dc.identifier.vancouvercitation Cracknell RH. Separation, preconcentration and determination of rare earth elements by inductively coupled plasma emission spectroscopy. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Physics, 1988 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/23192 en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Cracknell, R H AB - Rare earth elements, (REE), at ug g⁻¹ levels are used for studies of petrogenisis of different geological materials. For these studies, the REE must be determined precisely. An analytical program was established using an IL 200 Inductively Coupled Plasma, (ICP), spectrometer for the determination of the REE in various matrices, taking into consideration both matrix and spectral interferences, which were found to be severe in some cases. Dissolution of the sample, (0.4-1.0 g), was carried out using two methods; a microwave heated dissolution using a modified commercial microwave oven and a conventional oven heated closed pressure digestion vessel method. The results of these two methods were compared to determine the viability of using the more rapid microwave heated method. Separation of the REE from matrix elements was investigated using three cation exchange resins; Amber lite IR 120 (H), Zeocarb 225 and Dowex 50-WXS. A gradient acid elution method was established using a 15 cm by 20 mm Zeocarb 225 column. The sample was eluted with 140 ml of a 1.5 M H⁺ solution containing 0.75 M Cl⁻ and 0.75 M NO₃⁻, this fraction containing all the matrix elements. The REE were then eluted from the resin with 100 ml of 3 M HNO₃. The REE containing fraction was then reduced to 5 ml, diluted to 10 ml, and analysed for REE content. Liquid-liquid extraction methods for the separation of REE from matrix elements were investigated. It was found that the REE could be extracted synergistically from various buffered aqueous acidic media into chloroform, (CHCl₃), by hexafluoroacetylacetone, (HHFA), and quinoline. Acetylacetone, ( AcAc), was found to react with hexamethylenetetramine, (hexamine), when hexamine was used to buffer the aqueous phase during extraction procedures. The product of this reaction, 3.5-diacetyl-1.4-dihydro-2.6-dimethyl pyridine, was identified using X-ray crystallography. DA - 1988 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1988 T1 - Separation, preconcentration and determination of rare earth elements by inductively coupled plasma emission spectroscopy TI - Separation, preconcentration and determination of rare earth elements by inductively coupled plasma emission spectroscopy UR - http://hdl.handle.net/11427/23192 ER - en_ZA


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