Instrument Development: Development of Distance of Flight Mass Spectrometry Techniques for Chemical Measurement

有了这个奖项，化学部门的化学测量和成像（CMI）项目正在资助博士。Steven Ray和Gary Hieftje在印第安纳大学开发了一组基于新型质谱仪的化学测量技术，这种质谱仪被称为飞行距离质谱仪（DOF-MS）。DOF-MS技术测量每个离子在指定飞行周期内的距离，以确定离子的质荷比（m/z）。它具有许多潜在的优点，如测定非常高质量离子的m/z，提高测量速度，改进动态范围，可调和改进测量分辨率，以及后续离子收集用于其他技术的后续分析。混合DOF-TOF质谱仪在科学界的应用有望跨越许多领域，包括生物分析化学、微生物学、能源科学和分子生物学。Drs。Ray和Hieftje正在与当地质谱用户设施和太平洋西北国家实验室（PNNL）合作，以扩大用户基础并增强正在开发的新仪器的科学影响。参与研究项目的博士后和研究生经历了宝贵的跨学科培训。Drs。Ray和Hieftje还通过与罗斯-霍尔曼理工学院（当地一所以工程为重点的本科院校）和当地一所K- 12科学教育中心合作，开展了推广活动，以促进STEM学生的培训和教育。本项目的目标是开发一套基于飞行距离质谱（DOF-MS）的化学测量策略。在本项目中，开发了DOF-MS和TOF-MS的组合，作为在单个仪器中实现两种方法优势的手段。该DOF/TOF策略具有极宽的动态范围、快速的时间响应和广泛的覆盖范围，有可能显著改善色谱质谱检测。具体来说,Drs。Ray和Hieftje将DOF-MS的空间偏析与一种新型的电荷敏感离子探测器阵列（称为焦平面相机（FPC））耦合在一起，以同时测量在每个空间离散探测器元件上观察到的离子流，从而以非常宽的动态范围和出色的时间记录检测每个期望的质量电荷比（m/z）的m/z和丰度。此外，Ray博士和他的合作者正在开发一种Zoom-TOF-MS方法，该方法使用DOF-MS的离子聚焦策略和TOF-MS设置来提高仪器的质量分辨能力，同时只需要微小的功能和结构改变。Zoom-TOF-MS提供了更高的分辨率，以及质量分析仪的时间分辨率，提高了信噪比（S/N）。所支持的研究活动可能为科学界的广大部分提供一种有利的新工具。

With this award, the Chemical Measurements and Imaging (CMI) Program in the Division of Chemistry is funding Drs. Steven Ray and Gary Hieftje at Indiana University to develop a group of chemical measurement techniques based on a new type of mass spectrometer, known as the distance-of-flight mass spectrometer (DOF-MS). The DOF-MS technique measures the distance each ion travels over a specified flight period to determine the ion mass-to-charge ratio (m/z). It offers many potential advantages, such as the determination of m/z for ions of very high mass, increased speed of measurement, improved dynamic range, adjustable and improved measurement resolution, and the subsequent collection of ions for follow-on analysis by other techniques. The applicability of a hybrid DOF-TOF MS instrument by the scientific community is expected to span across many fields, including bioanalytical chemistry, microbiology, the energy scieces and molecular biology. Drs. Ray and Hieftje are working with local mass spectrometry user facilities and Pacific Northwest National Laboratory (PNNL) to broaden the user basis and enhance the scientific impact of the new instrument being developed. Postdoctoral and graduate students involved in the research project experience valuable interdisciplinary training. Drs. Ray and Hieftje also are engaged in outreach activities by parterning with Rose-Hulman Institute of Technology, a local engineering-focused undergraduate institution, and a local K- 12 science education center to promote STEM student training and education.The goal of this project is the development of a set of chemical measurement strategies based on distance-of-flight mass spectrometry (DOF-MS). In this project, a combination of DOF-MS and TOF-MS is developed as a means to realize the benefits of both approaches in a single instrument. This DOF/TOF strategy may have the potential to significantly improve chromatographic MS detection with extremely wide dynamic range, fast temporal response, and wide coverage. Specifically, Drs. Ray and Hieftje couple the spatial segregation of DOF-MS to a novel type of charge-sensitive ion detector array known as a focal-plane camera (FPC) to simultaneously measure the ion currents observed at every spatially discrete detector element, thus detecting the m/z and abundance for each desired mass-to-charge ratio (m/z) with very wide dynamic range and excellent temporal registry. In addition, Dr. Ray and his collaborators are developing a Zoom-TOF-MS approach that uses the ion focusing strategies of DOF-MS with a TOF-MS setup to improve the mass resolving power of the instrument while requiring only minor functional and architectural changes. Zoom-TOF-MS provides enhanced resolution as well as increased temporal resolution of the mass analyzer, and improves the signal-to-noise ratio (S/N). The supported research activities could potentially provide an enabling new tool for a broad segment of the scientific community.