对水中17O/16O和18O/16O比率的高精度测量。

High precision measurements of 17O/16O and 18O/16O ratios in H2O.

作者信息

Barkan Eugeni, Luz Boaz

机构信息

Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.

出版信息

Rapid Commun Mass Spectrom. 2005;19(24):3737-42. doi: 10.1002/rcm.2250.

DOI:10.1002/rcm.2250

PMID:16308852

Abstract

We have optimized the method of water fluorination using the solid reagent CoF3 to produce O2. This allows isotope ratio measurements by dual-inlet mass spectrometry with very high precision of 0.01 to 0.03/1000 for both delta17O and delta18O. Using this method, delta17O and delta18O of atmospheric O2 were determined as 12.08 and 23.88/1000 vs. VSMOW, respectively. Likewise, delta17O and delta18O of GISP were -13.12 and -24.73/1000, and for SLAP they were -29.48 and -55.11/1000 vs. VSMOW, respectively. Analysis of these data in a ln(delta17O + 1) vs. ln(delta18O + 1) plot yields a line with a regression coefficient (lambda) of 0.5279 +/- 0.0001 (R2 = 0.999999). We also determined the fractionation factors 17alpha and 18alpha in liquid-vapor equilibrium, and found that the ratio ln 17alpha/ln 18alpha is constant (0.529 +/- 0.001) over the temperature range 11.4 to 41.5 degrees C.

摘要

我们优化了使用固体试剂CoF₃进行水氟化以产生O₂的方法。这使得通过双入口质谱法进行同位素比率测量成为可能，对于δ¹⁷O和δ¹⁸O而言，测量精度非常高，可达0.01至0.03‰。使用该方法，大气O₂的δ¹⁷O和δ¹⁸O相对于VSMOW分别测定为12.08和23.88‰。同样，GISP的δ¹⁷O和δ¹⁸O分别为-13.12和-24.73‰，而对于SLAP，相对于VSMOW它们分别为-29.48和-55.11‰。在ln(δ¹⁷O + 1)对ln(δ¹⁸O + 1)的图中分析这些数据，得到一条回归系数（λ）为0.5279±0.0001（R² = 0.999999）的直线。我们还测定了液-气平衡中的分馏因子¹⁷α和¹⁸α，发现在11.4至41.5摄氏度的温度范围内，ln¹⁷α/ln¹⁸α的比值是恒定的（0.529±0.001）。