Dissertations and Theses @ UNI
Availability
Open Access Thesis
Keywords
Atomic absorption spectroscopy; Dysprosium; Erbium; Europium;
Abstract
The atomic absorption of dysprosium, erbium, and europium in nitrous oxide-acetylene flames was studied, using aqueous solutions, organic solvent-water systems, and 100% organic solutions. Efforts were made to relate the viscosity and concentration of organic solvents to absorption. The effects of organic solvents on chemical and interelement interference were studied. The precision of analysis by atomic absorption using both aqueous and organic solutions was compared with that of EDTA titrations. Enhancement in the absorption showed a linear dependence on the logarithm of the product of viscosity and boiling point of 100% organic solutions of the rare earth acetylacetonates. In alcohol-water mixtures, peak absorbances occurred when the viscosities of the solutions were in the range of 2.0-4.0 centipoise. When 1:1 v/v mixtures of acetone and ethylene glycol in water were used, a linear relationship between viscosity and volume% organic content resulted. No other solvent system studied showed this relationship. Dysprosium, erbium, and europium showed no significant differences in the shapes of absorbance curves in the various solvent systems. Above 50% concentration, the best solvents were acetonitrile and acetone while the poorest solvents were high boiling-point alcohols. Acetone, methyl ethyl ketone, and acetonitrile showed a linear relationship between absorbance and volume-percent organic content for all three r.are earths. A-1 A linear relationship between absorbance and concentration was noted within certain limits in aqueous, 70% ethanol, and 70% acetone solutions. A-2 When anions from sodium salts were mixed with the analyte in about 200:1 mole ratio in aqueous solutions, positive interference on absorption of dysprosium, erbium, and europium were observed. The use of 70% acetone solutions was effective in removing the interference caused by sodium salts of chloride, iodide, and acetate on absorption of europium. Europium absorption was reduced 20% in 70% ethanol solutions containing chloride, iodide, acetate, and nitrate ions. Interelement effects resulted in 20-50% enhancement for dysprosium, erbium, and europium. However, the introduction of organic solvents in the presence of interfering cations suppressed absorbance. The precision of atomic absorption using both aqueous and organic systems was inferior to that of EDTA titrations.
Year of Submission
1974
Degree Name
Master of Arts
Department
Department of Chemistry
First Advisor
Ching Woo
Second Advisor
James Chang
Third Advisor
Ralph Engardt
Date Original
1974
Object Description
1 PDF file (85 leaves)
Copyright
©1974 David L. Dozark
Language
en
File Format
application/pdf
Recommended Citation
Dozark, David L., "Some Comparative Studies of Atomic Absorption of Three Rare-Earth Elements of [i.e. In] Organic-Aqueous Solutions" (1974). Dissertations and Theses @ UNI. 2512.
https://scholarworks.uni.edu/etd/2512
Comments
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