Atmospheric Pressure Infrared MALDI Mass Spectrometry

该提议的主要目的是开发一种新颖的接口，用于使用大气压（AP）红外（IR）基质辅助激光解吸/电离（MALDI）方法将液体分离技术在线耦合到质谱仪（MS）。与传统的MALDI相反，在传统的MALDI中，离子在真空系统内形成。在AP MALDI，它们是在正常大气压力下生产的。AP MALDI首先使用紫外（UV）激光进行演示，后来商业化。它显示出与传统MALDI相当的灵敏度，对激光能量的大的耐受性，以及分析物离子的最小碎片。AP MALDI与离子阱质谱仪连接，为MALDI分析带来了独特的串联MS（或MS/MS）功能。由于AP UV-MALDI主要使用固体有机基质，因此它与常规UV-MALDI一样通常仅允许离线分析。使用IR激光器将允许使用显著更大数量的基质用于MS分析，包括液体基质。鉴于有机化合物在红外光谱范围内的优异吸收，AP IR-MALDI使得液体分离技术与MS的直接耦合成为可能，因此，在同一质量分析仪上具有用于液体分析的MALDI和电喷雾离子源的前景变得非常可行。拟议的商业应用：大气压IR-MALDI用于质谱仪与液体分离技术的接口以及离线分析。该方法在研究实验室、医院、工业和国防中具有许多生物和生物医学应用，其中利用蛋白质、肽、DNA和RNA的分析。SESI将该方法商业化是直截了当的。

The main purpose of this proposal is to develop a novel interface for on- line coupling of liquid separation techniques to a mass spectrometer (MS) using an atmospheric pressure (AP) infrared (IR) matrix-assisted laser desorption/ionization (MALDI) method. In contrast to conventional MALDI where ions are formed inside a vacuum system. In AP MALDI they are produced at normal atmospheric pressure. AP MALDI was first demonstrated and later commercialized using an ultraviolet (UV) laser. It showed sensitivity comparable to that of conventional MALDI, a large tolerance to the laser energy, and minimal fragmentation of analyte ions. AP MALDI interfaced with an ion trap mas spectrometer brings unique capability off tandem MS (or MS/MS) to MALDI analysis. Since AP UV-MALDI uses mostly solid organic matrices it like conventional UV- MALDI usually allows off-line analysis only. The use of an IR laser will allow one to use significantly larger number of matrices for MS analysis including liquid ones. Given excellent absorption or organic compounds in the IR spectral range the AP IR-MALDI makes possible direct coupling of liquid separation techniques =to MS, thus, the perspective of having both MALDI and electrospray ion sources for liquid analysis on the same mass analyzer becomes very feasible. PROPOSED COMMERCIAL APPLICATIONS: Atmospheric Pressure IR-MALDI for interfacing mass spectrometers to liquid separation techniques as well as for off-line analysis. This method has many biological and biomedical applications in research labs, hospitals, industry, and defense where analysis of proteins, peptides, DNA & RNA is utilized. Commercialization of the method by SESI is straightforward.