Carbon Isotopic Ratios of Crude Oils by Stable Isotope Mass Spectrometry

• Published in: Journal of the Japanese Association for Petroleum Technology Vol. 54; no. 2; pp. 107 - 110
• Main Authors: OKADA, Shizuko, TEZUKA, Machiko, TANAKA, Shigeyuki
• Format: Journal Article
• Language: Japanese; English
• Published: The Japanese Association for Petroleum Technology 1989
• ISSN: 0370-9868; 1881-4131
• DOI: 10.3720/japt.54.107

To know about characteristics of crude oils with mass spectrometer, the carbon isotopic ratios measurements of 86 samples of crude oil from foreign and domestic fields were carried out. A quartz tube was used as a combustion vessel and vanadium pentoxide as an oxidation agent. A mixture of crude oil and vanadium pentoxide placed in the quartz tube was vacuumed and then sealed. This was heated for 2 hours at 900°C in electric furnace. Produced carbon dioxide was introduced to mass spectrometer to determine isotopic ratio. Foreign oil samples showed -27.7--22.0‰, as δ13C values. Results of domestic crude oils showed -24.0--24.1‰ in Hokkaidou, -24.5--21.9‰ in Akita, -23.7--21.7‰ in Yamagata, and -24.8--21.3‰ in Niigata, as δ13C values, which agreed well with the results of the Tertiary period oil in North America.