title: Stable carbon and oxygen isotopic determination of sub-microgram quantities of CaCO3 to analyze individual foraminiferal shells.
abstract: We have developed an analytical system to determine stable isotopic compositions (delta13C and delta18O) of sub-microgram quantities of CaCO3 for the purpose of analyzing individual foraminiferal shells, using continuous-flow isotope ratio mass spectrometry (CF-IRMS). The system consists of a micro-volume CaCO3 decomposition tube, stainless steel CO2 purification vacuum line with a quantity-regulating unit, helium-purged CO2 purification line, gas chromatograph, and a CF-IRMS system. By using this system, we can determine stable carbon and oxygen isotopic compositions as low as 0.2 microg of CaCO3, with standard deviations of +/-0.10 per thousand for delta13C and +/-0.18 per thousand for delta18O within a 4-h reaction time and 30-min analysis period.
authors.affiliation: Division of Earth and Planetary Sciences, Graduate School of Science, Hokkaido University, Sapporo, Hokkaido, Japan. toyoho@ep.sci.hokudai.ac.jp
authors.forename: Toyoho
authors.initials: T
authors.lastname: Ishimura
authors.forename: Urumu
authors.initials: U
authors.lastname: Tsunogai
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Gamo
mesh_terms: D000818:Animals; D002113:Calcification, Physiologic; D002119:Calcium Carbonate / Q000032:analysis*; D002247:Carbon Isotopes / Q000032:analysis; D056890:Eukaryota / Q000737:chemistry / Q000378:metabolism*; D005580:Fossils; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry; D010103:Oxygen Isotopes / Q000032:analysis; D015203:Reproducibility of Results
chemical_list: D002247:Carbon Isotopes; D010103:Oxygen Isotopes; D002119:Calcium Carbonate