Stable isotope ratios (18O/16O, 13C/12C, and 17O/16O) in carbonates have contributed greatly to the understanding of Earth and planetary systems, climates, and history. The current method for measuring isotopologues of CO2 derived from CaCO3 is primarily gas-source isotope ratio mass spectroscopy (IRMS). However, IRMS has drawbacks, such as mass overlap by multiple CO2 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 18O/16O, 13C/12C, and 17O/16O analyses for microgram quantities of CaCO3 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 CO2 (equivalent to 2 μg of CaCO3) with standard errors of less than 0.08 ‰ for 18O/16O and 13C/12C (±0.136 ‰ and ±0.387 ‰ repeatability; n = 10). In larger samples of CO2, 0.68 μmol (or 68 μg of CaCO3), standard error is less than 0.04 ‰ for 18O/16O and 13C/12C (< ±0.1 ‰ repeatability; n = 10) and 0.03 ‰ for 17O/16O (±0.069 ‰ repeatability; n = 10). We also show, for the first time, the relationship between 17O/16O ratios measured using the TILDAS system and published δ17O 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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Henry's law constants of CHF2Cl in water at temperature T in K, KH(T) in M atm−1, were determined to be ln(KH(T))=−(11.1±1.5)+((2290±500)/T) at 313–363 K by means of a phase ratio variation headspace method. The temperature‐dependent rate constants for aqueous reactions of CHF2Cl with OH−, k(T) in M−1 s−1, were also determined to be 3.7×1013exp(−(11, 200/T)) at 313–353 K, by considering the gas–water equilibrium, the aqueous reaction at room temperature, and liquid‐phase diffusion control. The liquid‐phase diffusion control was approximated with a one‐dimensional diffusion first‐order irreversible chemical reaction model. The k(T) value we determined is 10 times (at 353 K) or 3 times (at 313 K) as large as the value reported (R. C. Downing, Fluorocarbon Refrigerants Handbook, Prentice Hall: Englewood Cliffs, NJ, 1988). This upward revision of k(T) indicates that the removal efficiency of CHF2Cl directly through the hydrolysis (CHF2Cl + OH−) is higher than previously expected at temperatures, such as 353 K, relevant to wet flue gas cleaning systems for ozone‐destruction substance‐destruction facilities. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 639–647, 2011