RUI: Elucidation of Matrix Effects in Laser Ablation Elemental Analysis through Absolute Quantification of Ablated Mass

在化学系化学测量和成像项目的支持下，以及刺激竞争性研究的既定项目（EPSCoR）的共同资助下，阿肯色州州立大学的乔纳森·梅尔滕教授和他的团队正在进行研究，旨在使我们周围的化学元素的测量更容易、更快、更便宜和“更环保”。“元素分析对许多领域都很重要，包括地质勘探、电子、制造业、农业、能源、国防和健康。 通常情况下，测量需要在测量前将样品溶解在昂贵的强酸中，这一过程可能需要数小时，并产生化学废物，安全处置成本很高。 Merten集团致力于提高对基于激光的替代方法的理解，这些方法更安全，更快。 具体来说，他们将脉冲激光引导到样品上，以产生比太阳表面更热的微小等离子体。 通过更好地控制和了解等离子体形成过程，他们正在努力改进基于激光的测量。 Merten博士和他的本科生还通过阿肯色州州立博物馆的项目接触到东北部阿肯色州社区，该博物馆位于阿肯色州州立大学的校园内，为阿肯色州东北部的农村人口提供服务。 这项工作有可能提供5000参与互动与公众使用自由形式的激光烧蚀实验在一级，安全联锁激光设置在博物馆，增加公众的知识和兴趣光谱学和改善干管道。 激光烧蚀（LA）分析方法，包括激光诱导击穿光谱（LIBS）和LA电感耦合等离子体分析，需要很少或不需要样品制备，是快速和（在LIBS的情况下）便携式。 不幸的是，他们是非常容易矩阵效应，这是很难理解，因为不均匀的等离子体？体积小，进化快。 Merten小组开发了一种技术，可以以高空间和时间分辨率绘制LA等离子体。 通过空间映射原子吸收光谱，可以计算气态等离子体的质量。 这种“光谱聚集”程序被用来直接和动态地提高对烧蚀后等离子体的理解，从而提高对烧蚀过程及其与元素分析方法中信号的关系的理解。 这种对总雾化质量及其化学计量发展的理解对于LA分析方法至关重要。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, and co-funding from the Established Program to Stimulate Competitive Research (EPSCoR), Professor Jonathan Merten and his group at Arkansas State University are pursuing research that aims to make the measurement of the chemical elements around us easier, faster, cheaper and "greener." Elemental analysis is important to many fields, including geologic exploration, electronics, manufacturing, agriculture, energy, defense, and health. Typically, the measurement requires that the sample be dissolved in expensive and powerful acids before measurement, a process that can take hours and generates chemical waste with high costs for safe disposal. The Merten group seeks to improve understanding of alternative laser-based methods which are safer and much faster. Specifically, they direct pulsed lasers at samples to generate tiny plasmas hotter than the surface of the sun. Through better control and understanding of the plasma formation process, they are working to improve the laser-based measurements. Dr. Merten and his undergraduate students are also reaching out to the Northeast Arkansas community through programs at the Arkansas State Museum, which serves a rural population in Northeast Arkansas from its location on the campus of Arkansas State University. This work has the potential to provide 5000 participatory interactions with the public using free-form laser-ablation experiments performed in a class I, safety-interlocked laser setup at the museum, increasing public knowledge of and interest in spectroscopy and improving the STEM pipeline. Laser-ablation (LA) analytical methods, including laser-induced breakdown spectroscopy (LIBS) and LA inductively coupled plasma analyses require little or no sample preparation and are rapid and (in the case of LIBS) portable. Unfortunately, they are extremely prone to matrix effects, which are difficult to understand because of the inhomogeneous plasma?s small size and rapid evolution. The Merten group has developed a technique that allows mapping of the LA plasma with high spatial and temporal resolution. By spatially mapping the atomic absorption spectrum, it is possible to calculate the mass of the gaseous plasma. This "spectral massing" procedure is being used to improve understanding of the post-ablation plasma directly and dynamically, thereby enhancing understanding of the ablation process and its relationship to the signal in elemental analysis methods. Such understanding of the total atomized mass and its stoichiometric development is critical for LA analytical methods.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.