Organic products from Ca14Co3 autoradiolysis: effects of thermal annealing
- 1. Universidad Nacional Autonoma de Mexico, Mexico City. Centro de Estudios Nucleares
- 2. Universidade Estadual de Campinas (Brazil). Inst. de Quimica
Description
Autoradiolysis of Ca14Co3 produces several different low molecular mass organic compounds which can be conveniently observed after ion exclusion-partition chromatographic separation of the dissolved sample, provided that the solid was prepared with high specific activity carbon-14 and has been stored for a sufficiently long period. Subsequent thermal annealing changes the distribution of these observed compounds, demonstrating that chemical reactions of the precursor species take place in the solid Ca14Co3 matrix. Specifically, the following products were observed after an autoradiolytic dose of 5 MGy: methanol, formaldehyde, formic acid, oxalic acid, glyoxylic acid, glycolic acid and acetic acid, with-G-values ranging from 5x10-6 to 2x10-3. Isochronal annealing to 5000C markedly changes the yields of carbon-14 labelled formic and acetic acids but has lesser effects on the other acidic products. This indicates that several different precursor species are present in the autoradiolyzed solid. (Author)
Abstract (Portuguese)
A autoradiolise do Ca14CO3 produz alguns compostos organicos de baixa massa molecular que sao separados e identificados, apos dissolucao do solido, por cromatografia liquida de particao-exclusao de ions, no caso de solido preparado em alta atividade especifica de carbono-14 e amarzenado por um periodo de tempo suficiente. Recozimentos termicos posteriores modificam a distribuicao dos compostos observados, demonstrando que sao induzidas reacoes quimicas das especies precursores na matriz solida do Ca14CO3. Especificamente, foram observados como produtos da autoradiolise ate 5 MGy, os compostos metanol, formaldeido e os acidos formico, oxalico, glioxilico, glicolico e acetico. Os rendimentos (valor G) estao na faixa de 5x10-6 a 2x10-3. O recozimento isocronico ate 5000C modificou significativamente os rendimentos dos acidos formico e acetico mas apresentaram menor efeito nos rendimentos dos outros acidos radiomarcados. Este indica a presenca de varios precursores no solido que sofreu a autoradiolise. (Autor)Additional details
Additional titles
- Original title (Portuguese)
- Produtos organicos da autoradiolise de Ca
Publishing Information
- Imprint Title
- Proceedings of the 1. General Congress of Nuclear Energy. v. 2
- Imprint Pagination
- 443 p.
- Journal Page Range
- v. 2 p. 217-220.
- Report number
- INIS-BR--537(v.2)
Conference
- Title
- 1. General Congress of Nuclear Energy.
- Dates
- 17-20 Mar 1986.
- Place
- Rio de Janeiro, RJ (Brazil).
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 17067617
- Subject category
- S38: RADIATION CHEMISTRY, RADIOCHEMISTRY AND NUCLEAR CHEMISTRY;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- ANNEALING; AUTORADIOLYSIS; CALCIUM CARBONATES; CARBON 14; LABELLED COMPOUNDS
- Descriptors DEC
- ALKALINE EARTH METAL COMPOUNDS; AUTOLYSIS; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; CALCIUM COMPOUNDS; CARBON COMPOUNDS; CARBON ISOTOPES; CARBONATES; CHEMICAL RADIATION EFFECTS; CHEMICAL REACTIONS; DECOMPOSITION; EVEN-EVEN NUCLEI; HEAT TREATMENTS; ISOTOPES; LIGHT NUCLEI; NUCLEI; OXYGEN COMPOUNDS; RADIATION EFFECTS; RADIOISOTOPES; RADIOLYSIS; YEARS LIVING RADIOISOTOPES
Optional Information
- Notes
- Imprint:Anais do 1. Congresso Geral de Energia Nuclear. v. 2.