A NOVEL HIGH-CAPACITY ION TRAP-QUADRUPOLE TANDEM MASS SPECTROMETER

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目及 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 我们描述了一种串联质谱仪原型，其设计目的是使链接扫描分析的效率比传统链接扫描仪器提高 100 倍以上。质谱仪的关键元件是新型高离子容量离子阱，与四极碰撞池和四极质量分析器（即 TrapqQ 配置）串联配置。该离子阱可以存储 >106 个离子，而不会显着降低其性能。对于 800 4000 m/z 范围内的离子，当前陷阱的质量分辨率为 100 450 半峰全宽，从而为在任何给定时间喷射到碰撞池中的离子提供 10 20 m/z 选择窗口。用于检测肽的质谱仪的灵敏度在低飞摩尔范围内。我们可以设想对仪器进行相对简单的修改，以提高其分辨率和灵敏度。我们测试了串联质谱仪，用于收集存储在陷阱中的所有离子的前体离子光谱，并证明我们可以选择性地检测非磷酸化肽混合物中的磷酸肽。基于该原型仪器，我们计划构建一个功能齐全的质谱仪模型，用于检测蛋白质上的修饰位点并以高速和高灵敏度分析其丰度。 目前，我们正在测试与正交飞行时间分析仪耦合的第二代仪器，以准确读出母离子和碎片离子的质量读数。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We describe a prototype tandem mass spectrometer that is designed to increase the efficiency of linked-scan analyses by >100-fold over conventional linked-scan instruments. The key element of the mass spectrometer is a novel high ion capacity ion trap, combined in tandem configuration with a quadrupole collision cell and a quadrupole mass analyzer (i.e. a TrapqQ configuration). This ion trap can store >106 ions without significant degradation of its performance. The current mass resolution of the trap is 100450 full width at half maximum for ions in the range 8004000 m/z, yielding a 1020 m/z selection window for ions ejected at any given time into the collision cell. The sensitivity of the mass spectrometer for detecting peptides is in the low femtomole range. We can envisage relatively straightforward modifications to the instrument that should improve both its resolution and sensitivity. We tested the tandem mass spectrometer for collecting precursor ion spectra of all the ions stored in the trap and demonstrated that we can selectively detect a phosphopeptide in a mixture of non-phosphorylated peptides. Based on this prototype instrument, we plan to construct a fully functional model of the mass spectrometer for detecting modification sites on proteins and profiling their abundances with high speed and sensitivity. Currently we are testing a second generation instrument coupled to an orthogonal time-of-flight analyzer for accurate mass readout of both the parent and fragment ions.