Instrumental Development: Infrared Multiphoton Dissociation Spectroscopy in a Cold Ion Trap

在化学研究仪器和设施：仪器开发计划(CRIF：ID)的支持下，北卡罗来纳大学教堂山分校的罗杰·米勒、托马斯·贝尔和加里·格利什教授将开发一种最先进的红外激光系统和用于红外多光子解离(IRMPD)光谱的冷却离子陷阱质谱仪。这一新仪器将实现分子离子的高分辨率红外光谱，目前只能使用非常昂贵的设备，如多用户设施中的自由电子激光。该项目将结合米勒团队在开发红外激光器方面的专业知识和GLISH集团在建造离子陷阱质谱仪方面的经验。Baer将增加补充水平的理论专业知识来解释实验光电子能谱。新仪器将使用新的光学参量振荡器技术来获得宽可调谐和建立腔以实现高功率。四极离子陷阱将使用电喷雾电离源，并将使用闭路循环低温制冷机进行冷却。仪器将能够记录的红外光谱将被PI用于在使用光谱学来确定多肽和蛋白质的二级结构方面取得进展。其他工作将包括离子溶剂化的气相研究，生物分子中的金属结合，以及离子解离动力学的研究。一名博士后助理和一名研究生将完成大部分仪器开发。一旦建成，它将作为一个高级工具，供三个研究小组的大约30名学生和博士后使用。私人投资促进机构还将使合作者能够使用该工具，并将传播成果以帮助其他人开发类似的工具。这种实验室规模的仪器将极大地扩大获得高分辨率IRMPD光谱学的机会，这可能在各种科学领域产生重大影响。PIS预计将该仪器的使用扩展到更多应用领域，如大生物分子的询问。

With support from the Chemistry Research Instrumentation and Facilities: Instrument Development (CRIF:ID) Program, Professors Roger Miller, Tomas Baer, and Gary Glish of the University of North Carolina at Chapel Hill will develop a state-of-the-art infrared laser system and cooled ion-trap mass spectrometer for infrared multiphoton dissociation (IRMPD) spectroscopy. This new instrument will enable high-resolution IR spectroscopy of molecular ions, which is currently only available using very expensive equipment such as free-electron lasers at multi-user facilities. The project will combine the expertise of Miller's group in developing IR lasers with the Glish group's experience building ion-trap mass spectrometers. Baer will add a complementary level of theoretical expertise to interpret experimental photoelectron spectra.The new instrumentation will use new optical parametric oscillator technology to obtain a wide tunability and a build-up cavity to achieve high power. The quadrupole ion trap will use an electrospray ionization source and will be cooled with a closed-cycle cryogenic refrigerator. The IR spectra that the instrument will be able to record will be used by the PIs to make progress in using spectroscopy to determine secondary structures of polypeptides and proteins. Other work will include gas-phase studies of ion solvation, metal binding in biomolecules, and studies of ion dissociation dynamics.A postdoctoral associate and a graduate student will do the bulk of the instrument development. Once constructed, it will be available as an advanced tool for approximately 30 students and postdocs in the three research groups. The PIs will also make the instrument accessible to collaborators and will disseminate results to aid others in developing similar instruments. This laboratory-scale instrumentation will greatly expand the accessibility to high-resolution IRMPD spectroscopy, which could have a large impact in a variety of scientific fields. Extending use of the instrument to more applied areas such as interrogation of large biomolecules is anticipated by the PIs.