【摘要】 近年来,非传统稳定同位素地球化学已成为新兴发展的研究领域,同位素双稀释剂技术是该领域的主流分析方法之一,但始终存在的困扰问题是如何进行同位素双稀释剂间以及稀释剂与样品间的最优混合。这两种混合比严重制约着同位素比值测试的准确度、精度和重现性。本文从同位素双稀释剂技术的数学原理出发,以Cr、Mo同位素为例,结合MonteCarlo误差模型,深入讨论和分析了两单稀释剂间比值（λ）及双稀释剂与自然样品间比值（p）的最优化数值模拟,得到了以双稀释剂⁵0（Cr）-⁵4（Cr）、⁹7（Mo）-¹⁰⁰Mo为例的λ、p值的最优取值范围。该数值模拟可适用于所有能够利用同位素双稀释剂技术的元素。在此基础上,就数值模拟结果如何应用于同位素双稀释剂的选择和组成标定也给予了详细说明,这为我国开展和使用同位素双稀释剂技术提供了基本思路和需要注意的关键问题,有助于推动同位素双稀释剂技术在我国地学界的广泛应用和发展。更多还原

【Abstract】 In recent years,the geochemistry of non-traditional stable isotopes is developing to be a novel studying field. The isotope double spike technique has been becoming one of the main analytical methods in determining isotopic composition. However,the always perplexing problem for researchers is of how to get the best mixing proportion between the two single spikes（λ）,and the optimal mixing ratio for the double spike and sample（p）. These two parameters severely restrict the accuracy,precision and the long reproducibility of the isotopes measurement. In this paper,we systematically elaborated on the mathematical principle of double spike technique as an example of chromium（Cr） and molybdenum（Mo） isotopes,and further discussed the numerical simulation optimization for getting above two parameters combined with the Monte-Carlo error model. The optimal simulated ratios of λ and p for⁵⁰Cr-⁵⁴Cr and⁹⁷Mo-¹⁰⁰Mo double spike are presented. The case study showed that this numerical simulation method for double spike can be applied to all elements with 4 or more isotopes. On the basis of the above,we presented the detailed description of how to use the numerical optimization results of double spike to select and calibrate double spike. Meanwhile,some trouble issues and the basic routine during using double spike are also presented for researchers who will engage in double spike. This paper will be helpful to promote the development of double spike and its extensively application in Chinese geosciences community.更多还原