TRACE ELEMENT DETERMINATIONS IN NATURAL MATERIALS BY ACTIVATION ANALYSIS

Conference · Tue Jan 01 04:00:00 EST 1963

OSTI ID:4104027

Ehmann, W D

Abundances of zirconium, hafnium, cadmium, antimony, tantalum, gold, platinum, and iridium have been determined in meteorites, tektites, deep-sea sediments, and various terrestrial materials by use of neutron activation analysis. Among the principal advantages of the method are its high sensitivity and freedom from errors due to reagent and laboratory contamination. These data have considerable significance in the fields of geochemistry and cosmochemistry. Each of these elements, except platinum, is separated after irradiation from the sample matrices by use of carriers and specific radiochemical separation techniques. Gold and platinum are determined simultaneously by separating and counting only gold. This is possible due to the decay of the irradiation- produced Pt/sup 199/ to its radioactive daughter, Au/sup 199/. Gamma-ray scintillation spectrometry allows selective counting of the Au/sup 199/ produced from the irradiation of gold and the Au /sup 199/ produced indirectly from the irradiation of platinum in the samples. All abundances are computed by comparison of gamma-ray counting rates of the extracted samples with the counting rates of standard samples of each element irradiated simultaneously. Certain of the abundance data for chondritic meteorites as determined in this work, including zirconium at 34 ppm, gold at 0.22 ppm, iridium at 0.49 ppm, and tantalum at 0.02 ppm, are in good agreement with the relatively few previous determinations found in the literature. However, other abundances, such as hafnium at 0.19 ppm in chondrites, are substantially different from previously reported data. The significance of these data as related to theories of meteorite formation and nucleosynthesis in the stars is briefly discussed. (auth)

• Research Organization: Kentucky. Univ., Lexington
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• NSA Number: NSA-18-008267
• OSTI ID: 4104027
• Report Number(s): CONF-151-4
• Country of Publication: United States
• Language: English

Related Subjects

ACTIVATION ANALYSIS
ANTIMONY
CHEMISTRY
COMPUTERS
DEPOSITS
EFFICIENCY
GAMMA SPECTROMETERS
GEOCHEMISTRY
GOLD
GOLD 199
HAFNIUM
IRIDIUM
METEORITES
NEUTRONS
PLATINUM
PLATINUM 199
QUANTITATIVE ANALYSIS
SCINTILLATION COUNTERS
SEA
STANDARDS
TANTALUM
TRACE AMOUNTS
ZIRCONIUM