A SIMPLE CO2 EXTRACTION METHOD FOR RADIOCARBON ANALYSES OF DISSOLVED INORGANIC CARBON IN WATER SAMPLES WITHOUT A CARRIER GAS
| Autor: | Hiroko Handa, Masayo Minami, Hiroshi A. Takahashi |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
010506 paleontology
Archeology Supercritical carbon dioxide 010504 meteorology & atmospheric sciences Chemistry Analytical chemistry chemistry.chemical_element Fraction (chemistry) Trapping Fractionation 01 natural sciences law.invention law Yield (chemistry) Dissolved organic carbon General Earth and Planetary Sciences Radiocarbon dating Carbon 0105 earth and related environmental sciences |
| Zdroj: | Radiocarbon. 63:1339-1353 |
| ISSN: | 1945-5755 0033-8222 |
| Popis: | We developed a simple and cost-effective method for extracting carbon from dissolved inorganic carbon (DIC) in water samples without a carrier gas. This method only slightly modifies the existing vacuum line for CO2 purification in radiocarbon research laboratories by connecting several reservoirs and traps. The procedure consists of repeated cycles of CO2 extraction from water into the headspace of the reaction container, expansion of the extracted gas into the vacuum line, and cryogenic trapping of CO2. High CO2 yield (∼98%) was obtained from a variety of water samples with a wide range of DIC concentrations (0.4–100 mmol·L−1, in the case of 1.2 mgC). The δ13C fractionation depended on the CO2 yield, while the 14C concentration was constant within the error range, regardless of the CO2 yield. The average δ13C discrepancy between the results of this method and direct analyses made using the GC-IRMS was 0.02 ± 0.06‰. The standard deviations (1σ) in fraction of modern carbon (F14C) ranged from 0.0002 to 0.0004 for waters below 0.01 of F14C, and below 0.8% of F14C values for waters above 0.1. We conclude that this method is useful for effectively extracting CO2 from DIC in water and yields accurate 14C data. |
| Databáze: | OpenAIRE |
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