不同检测方法对氢氧同位素分馏的影响
The Impact of Hydrogen and Oxygen Isotope Mass Fractionation for Different Detection Methods
-
摘要: 氢氧同位素的检测方法由最初的离线双路进样同位素比质谱法(Dual-inlet IRMS),发展到自动化程度较高的连续流水平衡法(Gasbench-IRMS)检测方法以及现阶段正在研究使用的热转换元素分析同位素比质谱法(TC/EA-IRMS)。为了探讨不同检测方法对氢氧同位素分馏的影响以及各方法的优缺点,文章应用Dual-inlet IRMS、GasbenchⅡ-IRMS、TC/EA-IRMS三种检测方法对四种不同水样的氢氧同位素进行检测,并用国际标准和国家标准对检测结果进行校正。结果表明,Dual-inlet IRMS法检测氢同位素的精密度高,重现性好;Gasbench-IRMS法检测氢同位素的结果重现性较差;Dual-inlet IRMS和Gasbench-IRMS法检测氧同位素要比TC/EA-IRMS法的精密度高,重现性好。用TC/EA-IRMS法检测氢氧同位素,分别用国际标准和国家标准校正,δD值的最大绝对偏差为1.13‰,δ18O值的最大绝对偏差为0.27‰。测定不同水样的氢氧同位素时,连续流GasbenchⅡ-IRMS测定氧同位素较有优势,而TC/EA-IRMS测定氢同位素比较有优势。样品测试过程中选用的校正标准不同,检测结果也存在一定的误差。Abstract: Since there are a number of ways to measure hydrogen and oxygen isotopes by mass fractionation, this paper describes the comparison between three detection methods on four different water samples. Two different standards were used to calibrate the results. The results indicate that the Dual-inlet IRMS off-line method has the best reproducibility for the detection of hydrogen isotopes, while the Gasbench Ⅱ-IRMS online analytical method has poor reproducibility. The Gasbench Ⅱ-IRMS online analytical method and Dual-inlet IRMS off-line method provide better oxygen isotope composition data in precision and reproducibility than the TC/EA-IRMS method. Both international standards and national standards were used to calibrate the data obtained by TC/EA-IRMS respectively. Maximum absolute deviation of hydrogen isotope composition data was 1.13‰, and oxygen isotope composition data is 0.27‰. With a different water sample analysis, the Gasbench Ⅱ-IRMS online analytical method performed best for the oxygen isotope composition analysis and TC/EA-IRMS method for the hydrogen isotope composition analysis. The results differed with different calibration standards.
-
-
计量
- 文章访问数: 1522
- PDF下载数: 3
- 施引文献: 0
下载: