Published 1989 | Version v1
Miscellaneous Open

Rare earths determination methods, with separation pre-irradiation followed by neutron activation. Utilization of brazilian standards BB-I and GB-I

Creators

  • 1. Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo, SP (Brazil). Div. de Radioquimica
  • 2. Sao Paulo Univ., SP (Brazil). Dept. de Geofisica

Description

In order to determine the rare earth elements (REE) in rocks, by neutron activation analysis, a group separation, before irradiation, was developed. The Brazilian geological standards BB-1 and GB-1, from Instituto de Geociencias da Universidade da Bahia, were analyzed. The method was based on acid digestion of the samples, cation exchange separation with a Dowex 50WX8 column and coprecipitation of the REE with calcium oxalate. Interferents like U, Th, Ta and Fe were eliminated. The concentration values of ten REE (La, Ce, Pr, Nd, Sm, Eu, Tb, Ho, Yb, and Lu) were determined. The analysis of Pr brought a contribution to the knowledge of the REE contents in these geological standards, since there are not yet results in the literature. The other REE data obtained were compared with literature values and some discrepancies are discussed. (author)

Abstract (Portuguese)

Foi desenvolvido um metodo de separacao dos elementos terras raras |ETR), previo a irradiacao, para a determinacao destes elementos em rochas, por analise por ativacao com neutrons. Foram analisados os padroes geologicos brasileiros BB-1 e GB-1, fornecidos pelo Instituto de Geociencias da Universidade Federal da Bahia. O metodo consistiu na digestao acida das rochas, retencao dos ETR em uma resina Dowex 50WX8, posterior eluicao com HCl 6M e coprecipitacao dos ETR com oxalato de calcio. Desse modo, inerferentes como U, Th, Ta e Fe foram eliminados. Determinaram-se dez elementos da familia (La, Ce, Pr, Nd, Sm, Eu, Tb, Mo, Yb e Lu). A determinacao de Pr constitui uma contribuicao importante ao conhecimento do teor dos ETR nesses padroes, desde que ainda nao existem resultados na literatura. Os valores obtidos para os demais ETR foram comparados com os dados ja existentes e algumas discrepancias sao discutidas. (autor)

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Additional details

Additional titles

Original title (Portuguese)
Metodo de determinacao de terras raras, com separacao pre-irradiacao seguida de ativacao neutronica. Aplicacao aos padroes brasileiros BB-I e GB-I

Publishing Information

Imprint Pagination
11 p.
Report number
INIS-BR--1761

Conference

Title
2. Brazilian Congress of Geochemistry.
Dates
1-6 Oct 1989.
Place
Rio de Janeiro, RJ (Brazil).

INIS

Country of Publication
Brazil
Country of Input or Organization
Brazil
INIS RN
21005164
Subject category
S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY;
Resource subtype / Literary indicator
Conference
Descriptors DEI
CALCIUM COMPOUNDS; COPRECIPITATION; NEUTRON ACTIVATION ANALYSIS; RARE EARTHS; ROCKS; SPECIFICATIONS
Descriptors DEC
ACTIVATION ANALYSIS; ALKALINE EARTH METAL COMPOUNDS; CHEMICAL ANALYSIS; ELEMENTS; METALS; NONDESTRUCTIVE ANALYSIS; PRECIPITATION; SEPARATION PROCESSES