Evaluation of carrier gases for high-precision water isotopic measurements by cavity ring-down laser spectroscopy |
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| Authors: | Meng Xing Weiguo Liu |
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| Affiliation: | 1. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, China;2. School of Human Settlement and Civil Engineering, Xi’an Jiao Tong University, Xi’an, China |
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| Abstract: | The carrier gas is important for obtaining stable, precise hydrogen and oxygen isotopic ratios in water samples using cavity ring-down laser spectroscopy. The δ2H and δ18O variations were investigated using four carrier gases under two microcombustion conditions. Although most deviations of δ2H and δ18O values were within the standard deviation of the instrument, statistical analysis indicated that carrier gas provided by a drying tube with higher water background was not suitable for cavity ring-down laser spectroscopy. In addition, the microcombustion on condition did not significantly improve the precision and accuracy of δ2H and δ18O measurements. Therefore, the best method for achieving highly precise results involved the use of low water containing compressed air as the carrier gas with the microcombustion warm condition. |
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| Keywords: | Carrier gas cavity ring-down laser spectroscopy water isotope |
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