Infrared Laser Ambient Mass Spectrometry

在化学系化学测量和成像项目的支持下，Murray教授和他在路易斯安那州立大学和巴吞鲁日农业机械学院的团队将开发新的仪器，用于在环境条件下快速进行化学和生化分析。在该项目下开发的仪器将应用于法医学、交通安全、医学和其他不同领域。默里博士的研究小组将使用脉冲红外激光直接从环境中的样品中烧蚀材料。烧蚀后的物质被捕获在一个小的溶剂液滴或样品靶上进行质谱分析。与传统的质谱法不同，大样本不需要处理和加载到仪器中；激光只去除一小部分用于分析。该研究的双重目标是对红外激光烧蚀过程的基本理解，以及将这些知识应用于新型化学分析仪器的设计和实现。激光烧蚀的基本问题是烧蚀材料的尺寸和数量以及对激光波长、脉冲能量和样品成分的依赖。高速摄影，广谱粒度和有限元建模将用于探测和优化材料去除过程。环境激光消融采样将用于生化成像和远程机器人采样。激光消融采样允许采样和分析之间的组分分离，以扩大动态范围。远程机器人采样阶段将对大型三维物体进行采样，用于各种应用，例如外科手术过程中的实时质谱分析或检查站行李爆炸残留物分析。这个项目的教育部分继续关注为弱势群体扩大教育机会，这是路易斯安那州立大学化学项目的亮点。一个动手的质谱演示也将开发，将向学生展示质谱的力量和效用，同时连接到技术背后的基础化学和物理。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Murray and his group at Louisiana State University and Agricultural and Mechanical College in Baton Rouge will develop new instrumentation for rapid chemical and biochemical analysis under ambient conditions. The instruments developed under this project will have applications in forensics, transportation security, medicine, and other diverse areas. Dr. Murray's group will use pulsed infrared lasers to ablate material directly from samples in the environment. The ablated material is captured in a small solvent droplet or on a sample target for mass spectrometry analysis. Unlike conventional mass spectrometry, the bulk sample does not need to be processed and loaded into the instrument; the laser removes only a small portion for analysis. The dual goals of the research are a fundamental understanding of the infrared laser ablation process and the application of this knowledge to the design and implementation of novel chemical analysis instrumentation. The fundamental issues of laser ablation are the size and quantity of the ablated material and the dependence on the laser wavelength, pulse energy, and sample composition. High-speed photography, broad-spectrum particle sizing, and finite element modeling will be used to probe and optimize the material removal process. Ambient laser ablation sampling will be used for biochemical imaging and remote robotic sampling. Laser ablation sampling allows component separation between sampling and analysis for expanded dynamic range. The remote robotic sampling stage will sample large three-dimensional objects for diverse applications such as real-time mass spectrometry during a surgical procedure or checkpoint baggage analysis for explosive residue. The educational component of this project continues the focus on expanding educational opportunities for underrepresented groups that is the highlight of the LSU chemistry program. A hands-on mass spectrometry demonstration will also be developed that will show students the power and utility of mass spectrometry while linking to the fundamental chemistry and physics behind the technique.