Theoretical foundations of the correction factors for the analysis of the relative variations of 13C/12C and 18O/16O ratios, by mass spectrometry
Creators
- 1. UNESP, Botucatu (Brazil). Inst. Basico de Biologia Medica e Agricola
- 2. Centro de Energia Nuclear na Agricultura, Piracicaba (Brazil)
- 3. Sao Paulo Univ., Piracicaba (Brazil). Escola Superior de Agricultura Luiz de Queiroz
Description
A review is made of analytical procedures to calculate correction factors, proposed by CRAIG (1957) to determine isotopic enrichment relating to the international PBD standard sample, obtained from analysis of carbon dioxide gas samples by mass spectrometry. Using such correction factors, the isotopic composition of the secondary CENA-standard sample is characterized through calculation of the main isotopic ratios of this sample. It is then possible to obtain correction factors for the determination of the isotopic enrichment relating to the secondary CENA-standard sample itself. New correction factors are proposed taking into account the interference of various isotopic species and the variability in sample and secondary standard preparation, that make possible the detemination of carbon-13 and oxygen-18 isotopic enrichment relating to the international PBD standard sample, with a total analytical error σ = + - 0.20/00 in normal routine work. (Author)
Abstract (Portuguese)
Sao revistos os procedimentos analiticos que conduzem ao calculo dos fatores de correcao, propostos por CRAIG (1957), para a determinacao dos enriquecimentos isotopicos, relativos ao padrao internacional PDB, obtidos a partir da analise, por espectrometira de massa, de amostras gasosas do dioxido de carbono. Utilizando tais fatores de correcao fica caracterizada a composicao isotopica do padrao secundario CENA-std pelo calculo das principais razoes isotopicas deste padrao. E possivel entao, obter os fatores de correcao para a determinacao dos enriquecimentos isotopicos relativos ao proprio padrao secundario CENA-std. Considerando as interferencias das varias especies isotopicas e a variabilidade no preparo da amostra e do padrao secundario, sao propostos novos fatores de correcao que possibilitam os enriquecimentos isotopicos relativos ao padrao internacional PDB, do carbono-13 e oxigenio-18, com erro analitico total σ = + - 0,20/00 em rotina normal de trabalho. (Autor)Additional details
Additional titles
- Original title (Portuguese)
- Fundamentos teoricos dos fatores de correcao, para a analise das variacoes relativas das razoes
Publishing Information
- Journal Title
- Energ. Nucl. Agric.
- Journal Volume
- 4
- Journal Issue
- 1
- Series
- Energ. Nucl. Agric.
- Journal Page Range
- 41-58
- ISSN
- 0100-3593
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 14760467
- Subject category
- S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY;
- Descriptors DEI
- CALIBRATION STANDARDS; CARBON ISOTOPES; CARBON 12; CARBON 13; CORRECTIONS; INTERLABORATORY COMPARISONS; ISOTOPE RATIO; OXYGEN ISOTOPES; OXYGEN 16; OXYGEN 18; STANDARDIZATION
- Descriptors DEC
- EVEN-EVEN NUCLEI; EVEN-ODD NUCLEI; ISOTOPES; LIGHT NUCLEI; NUCLEI; STABLE ISOTOPES