Analysis of nano-quantities of geo-materials by Total-Reflectance X-Ray Fluorescence

通过全反射 X 射线荧光分析地质材料的纳米量

• 批准号: RTI-2017-00292
• 负责人: vanHinsberg, Vincent
• 金额: $ 10.93万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=616624
• 关键词: Analysis; nano; quantities; geo; materials

Geoscience research takes place at progressively smaller scales, either out of necessity, for example in the simulation of high-pressure high-temperature domains in the Earth where pressure inversely scales with experiment sample size, or by design, for example to interrogate the geological record at increasingly finer time-resolution. This trend produces significant analytical challenges related to the need to quantify the complete periodic table in ever smaller sample quantities. The Total Reflectance X-Ray Fluorescence Spectrometer (TXRF) requested here is ideally suited to overcome these issues. TXRF uses a grazing angle (0.1°) primary X-Ray beam to generate secondary fluorescence X-rays in a thin film of evaporated fluid, suspended solid or rock wafer. The thin-film grazing-angle configuration eliminates element interferences and matrix effects, and allows the detector to be mounted very close to the sample to optimize count rates. As a result, TXRF is characterized by very low backgrounds and can detect elements down to ppb-levels. Moreover, it is non-destructive, can analyse most of the periodic table, and can handle concentrations ranging from mass % to ppb simultaneously. The TXRF instrument will enable a wide diversity of research projects conducted by the co-applicants, including their Discovery Grant research programs. It will allow for the small quantities of fluids and solids synthesized in experiments to be analysed for major and trace elements. This experimental research aims to develop tools to reconstruct the compositions of fluids from the minerals that precipitated from them, and constrain the stability of metals in aqueous fluids to allow for thermodynamic modelling of ore-fluid evolution. The ability to analyse complex fluids and brines without any dilution or other sample pre-processing will be used in studies to determine the cycling of elements between marine sediments and seawater, and to determine whether the sediment acts as a net sink or source of these elements. It will also be applied to understand the environmental impact of acidic metal-laden brines released by Kawah Ijen volcano in Indonesia and to explore the mobility of metals in geothermal fluids in Iceland. Studies of zoned crystals and bedded meta-sediments benefit from the improved sampling resolution enabled by TXRF, which allows for the evolution of magmatic systems and sedimentary basins, respectively, to be investigated at much finer temporal scales. This research greatly enhances our understanding of element cycles and human's impact on these, it allows for past environments to be reconstructed and used as a proxy in forward modelling of climate change, and will provide insights into ore formation, all of which address key societal uncertainties for the future related to pollution, climate change and dwindling natural resources.

地球科学研究是在逐渐较小的尺度上进行的，例如，在地球上高压高温度域的模拟中，在这种模拟中，压力呈压力呈实验样本量或设计，例如以越来越精细的时间分辨率询问地质记录。这种趋势会引起与需要量化较小的样品数量的完整周期表相关的重大分析挑战。此处请求的总反射率X射线荧光光谱仪（TXRF）非常适合克服这些问题。 TXRF使用放牧角（0.1°）主X射线束在蒸发液，悬浮固体或岩石晶片的薄膜中生成次级荧光X射线。薄膜放牧角构型消除了元素的相互作用和矩阵效果，并允许将检测器安装到非常接近样品以优化计数速率的情况下。结果，TXRF的特征是背景非常低，可以检测到PPB级的元素。此外，它是无损的，可以分析大多数元素周期表，并且可以简单地处理从质量％到PPB的浓度。 TXRF工具将使共同申请者进行的各种研究项目，包括他们的发现赠款研究计划。它将允许对实验中合成的少量流体和固体进行分析，以分析主要和微量元素。这项实验研究旨在开发工具，以重建从中沉入的矿物质的液体的组成，并限制水中金属在水性流体中的稳定性，以允许对矿石 - 流体进化的热力学建模。在研究中将使用无稀释或其他样品预处理的复杂烟和盐水的能力来确定海洋沉积物和海水之间元素的循环，并确定沉积物是否充当这些元素的净下水道或这些元素的来源。它还将用于了解印度尼西亚的卡瓦·伊恩（Kawah Ijen）火山释放的酸性金属盐水的环境影响，并探索冰岛地热液中金属的迁移率。 TXRF实现了改进的采样分辨率，对分区晶体和层状的元素的研究有益于岩浆系统和沉积贝司的进化，可以在许多最终的临时量表中进行研究。这项研究极大地增强了我们对元素周期和人类对这些元素的影响的理解，它允许重建过去的环境并用作气候变化的正向建模的代理，并将为矿石形成提供洞察力，所有这些都解决了与未来有关的与未来有关的污染，气候变化，气候变化和枯萎的自然资源的关键社会不确定性。