TY - JOUR
T1 - High-Precision Simultaneous 18 O/ 16 O, 13 C/ 12 C, and 17 O/ 16 O Analyses for Microgram Quantities of CaCO 3 by Tunable Infrared Laser Absorption Spectroscopy
AU - Sakai, Saburo
AU - Matsuda, Shinichi
AU - Hikida, Toshihide
AU - Shimono, Akio
AU - Mcmanus, J. Barry
AU - Zahniser, Mark
AU - Nelson, David
AU - Dettman, David L.
AU - Yang, Danzhou
AU - Ohkouchi, Naohiko
N1 - Funding Information:
We gratefully acknowledge Asahiko Taira (JAMSTEC), Masahiro Kawasaki (RIHN), Yutaka Matsumi (Nagoya University), Akihiro Kano (University of Tokyo), Hitoshi Yanagida (Sanyu Plant Service Co. Ltd.), and Haruhisa Yano (Address Service Co. Ltd.) for their support in establishing this system. Partial funding of this work was provided by grants-in-aid for scientific research by MEXT/JSPS (No. 23681006 and 15H03756 and 15KK0179) to S.S.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/11/7
Y1 - 2017/11/7
N2 - Stable isotope ratios ( 18 O/ 16 O, 13 C/ 12 C, and 17 O/ 16 O) in carbonates have contributed greatly to the understanding of Earth and planetary systems, climates, and history. The current method for measuring isotopologues of CO 2 derived from CaCO 3 is primarily gas-source isotope ratio mass spectroscopy (IRMS). However, IRMS has drawbacks, such as mass overlap by multiple CO 2 isotopologues and contaminants, the requirement of careful sample purification, and the use of major instrumentation needing permanent installation and a high power electrical supply. Here, we report simultaneous 18 O/ 16 O, 13 C/ 12 C, and 17 O/ 16 O analyses for microgram quantities of CaCO 3 using a tunable mid-infrared laser absorption spectroscopy (TILDAS) system, which has no mass overlap problem and yields high sensitivity/precision measurements on small samples, as small as 0.02 μmol of CO 2 (equivalent to 2 μg of CaCO 3 ) with standard errors of less than 0.08 ‰ for 18 O/ 16 O and 13 C/ 12 C (±0.136 ‰ and ±0.387 ‰ repeatability; n = 10). In larger samples of CO 2 , 0.68 μmol (or 68 μg of CaCO 3 ), standard error is less than 0.04 ‰ for 18 O/ 16 O and 13 C/ 12 C (< ±0.1 ‰ repeatability; n = 10) and 0.03 ‰ for 17 O/ 16 O (±0.069 ‰ repeatability; n = 10). We also show, for the first time, the relationship between 17 O/ 16 O ratios measured using the TILDAS system and published 17 O values of international standard materials (NBS-18 and -19) measured by IRMS. The benchtop TILDAS system, with cryogen-free sample preparation vacuum lines for microgram quantities of carbonates, is therefore a significant advance in carbonate stable isotope ratio geochemistry and is a new alternative to conventional IRMS.
AB - Stable isotope ratios ( 18 O/ 16 O, 13 C/ 12 C, and 17 O/ 16 O) in carbonates have contributed greatly to the understanding of Earth and planetary systems, climates, and history. The current method for measuring isotopologues of CO 2 derived from CaCO 3 is primarily gas-source isotope ratio mass spectroscopy (IRMS). However, IRMS has drawbacks, such as mass overlap by multiple CO 2 isotopologues and contaminants, the requirement of careful sample purification, and the use of major instrumentation needing permanent installation and a high power electrical supply. Here, we report simultaneous 18 O/ 16 O, 13 C/ 12 C, and 17 O/ 16 O analyses for microgram quantities of CaCO 3 using a tunable mid-infrared laser absorption spectroscopy (TILDAS) system, which has no mass overlap problem and yields high sensitivity/precision measurements on small samples, as small as 0.02 μmol of CO 2 (equivalent to 2 μg of CaCO 3 ) with standard errors of less than 0.08 ‰ for 18 O/ 16 O and 13 C/ 12 C (±0.136 ‰ and ±0.387 ‰ repeatability; n = 10). In larger samples of CO 2 , 0.68 μmol (or 68 μg of CaCO 3 ), standard error is less than 0.04 ‰ for 18 O/ 16 O and 13 C/ 12 C (< ±0.1 ‰ repeatability; n = 10) and 0.03 ‰ for 17 O/ 16 O (±0.069 ‰ repeatability; n = 10). We also show, for the first time, the relationship between 17 O/ 16 O ratios measured using the TILDAS system and published 17 O values of international standard materials (NBS-18 and -19) measured by IRMS. The benchtop TILDAS system, with cryogen-free sample preparation vacuum lines for microgram quantities of carbonates, is therefore a significant advance in carbonate stable isotope ratio geochemistry and is a new alternative to conventional IRMS.
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U2 - 10.1021/acs.analchem.7b03582
DO - 10.1021/acs.analchem.7b03582
M3 - Article
C2 - 28937751
AN - SCOPUS:85056283895
VL - 89
SP - 11846
EP - 11852
JO - Analytical Chemistry
JF - Analytical Chemistry
SN - 0003-2700
IS - 21
ER -