@article{oai:niigata-u.repo.nii.ac.jp:02000226, author = {Satish-Kumar, Madhusoodhan and Kiran, Sasidharan and Abe, Miyako}, journal = {Science reports of Niigata University. (Geology)}, month = {Mar}, note = {A new Thermo Scientific^ MAT-253 isotope ratio mass spectrometer was installed at Department of Geology, Niigata University, Japan under the MEXT Grant-in-Aid for Scientific Research on Innovative Areas. The mass spectrometer was set up for carbon and oxygen isotope measurement of small volume CO_2 samples. A new inlet vacuum line was constructed for transferring standard gas, to inlet externally prepared CO_2 gas samples and transfer CO_2 gas prepared in the online carbonate reaction system. The line is evacuated using a turbo molecular pump and pneumatically activated valves controlled by an electrical control board. The vacuum line also includes a reference CO_2 gas (Working Standard) reservoir and a laboratory standard CO_2 gas (Machine Standard) reservoir for routine analyses, as well as SF_6 reference gas reservoirs. The preparation line can hold high vacuum conditions without appreciable leaks for several hours, required for the completion of a single session of sample measurements. Long-term laboratory standard measurement results are reported here, which shows an average of δ^<13>C_<(V-PDB)> value of ‒29.796 ± 0.041‰ and δ^<18>O_<(V-SMOW)> value of 3.971 ± 0.062‰ (n = 44; 1σ). During a period of one year of analysis, a drift of 0.04‰ for both carbon and oxygen is observed for the reference CO_2 gas. NIST standards (NBS-20 limestone and NBS-21 graphite) and a laboratory diamond standard were analyzed to characterize the minimum volume of sample required to obtain carbon and oxygen isotopic composition with accuracy and precision <0.1‰. We also report here the routine analytical procedure for carbonate samples (calcite/aragonite and dolomite/siderite/magnesite) and elemental carbon (graphite and diamond).}, pages = {21--42}, title = {A new inlet system for microscale carbon and oxygen stable isotope analysis using dual inlet isotope ratio mass spectrometer at Niigata University, Japan}, volume = {36}, year = {2021} }