On-line high-precision stable hydrogen isotopic analyses on nanoliter water samples.
Anal Chem
; 73(15): 3570-5, 2001 Aug 01.
Article
em En
| MEDLINE
| ID: mdl-11510820
ABSTRACT
We describe a new on-line chromium reduction technique for the measurement of stable hydrogen (deltaD) isotopes in waters using continuous-flow isotope ratio mass spectrometry. The on-line Cr reduction method has low intersample memory effects (< 1%) and excellent precision and accuracy for deltaD (+/-0.5% and was used to analyze waters samples as small as 50 nL. The on-line Cr method has a number of significant advantages over conventional offline Zn and U reduction and on-line carbon-based pyrolysis techniques. A single Cr reactor can be used to analyze approximately 1,000 water samples using an injection volume of 0.5 microL, with an individual sample analysis time of 4 min. Intersample memory effects are negligible. The Cr reactor temperature of 1050 degree C is easily attainable on standard elemental analyzers and so does not require the specialized and costly high-temperature furnaces of carbon-based pyrolysis reactors. Furthermore, hydrogen isotopes in extremely small water samples in the 100-nL range or less can be easily measured; hence, this new method opens up a number of exciting application areas in earth and environmental sciences, for example, natural abundance deltaD measurements of individual fluid inclusions in geologic materials using a laser source and measurements of body fluids in physiological and metabolic research.
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Base de dados:
MEDLINE
Assunto principal:
Poluentes Radioativos da Água
/
Água
/
Monitoramento Ambiental
Idioma:
En
Ano de publicação:
2001
Tipo de documento:
Article