Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan.
Anal Chem. 2011 Oct 1;83(19):7486-91. doi: 10.1021/ac201706g. Epub 2011 Aug 30.
Multiple prompt γ-ray analysis (MPGA) and conventional neutron-induced prompt γ-ray analysis (PGA) are nondestructive analytical methods for bulk chemical compositions, and their analytical capabilities were compared for elemental analyses of geological and cosmochemical samples. Detection sensitivities of PGA are often restricted by poor signal-to-noise ratios and interferences from different origins. MPGA can substantially reduce the background level, especially for hydrogenous samples, relative to PGA, which opens up a possibility to use lower energy prompt γ-rays of some trace elements. Although it is one of the major constituent elements of rock samples, Mg is hard to be determined by PGA. With MPGA, Mg contents could be determined with reasonable consistency with their corresponding recommended values in geological and cosmochemical samples by carefully selecting suitable coincident prompt γ-ray energy pairs without interference correction. MPGA was applied to a hydrogenous meteorite, Ivuna, which contains H at 2% mass level. MPGA detection limits for most of the elements studied can be reduced up to 1 order of magnitude when compared with PGA detection limits under the present experimental conditions.
多道瞬发γ射线分析（MPGA）和常规中子感生瞬发γ射线分析（PGA）是用于测定块状化学组成的非破坏性分析方法，本工作比较了这两种方法对地质和宇宙化学样品进行元素分析的能力。PGA 的检测灵敏度通常受到信噪比差和来自不同来源的干扰的限制。与 PGA 相比，MPGA 可以大大降低背景水平，特别是对于含氢样品，这为使用某些微量元素的低能量瞬发γ射线提供了可能性。尽管 Mg 是岩石样品的主要组成元素之一，但用 PGA 很难测定。通过 MPGA，可以在不进行干扰校正的情况下，通过仔细选择合适的符合瞬发γ射线能量对，用 MPGA 来测定地质和宇宙化学样品中的 Mg 含量，其结果与 Mg 的推荐值具有较好的一致性。将 MPGA 应用于含有 2%质量水平 H 的含氢陨石 Ivuna，与 PGA 相比，在当前实验条件下，研究的大多数元素的 MPGA 检测限可以降低 1 个数量级。
