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

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们描述了一个原型串联质谱仪，它的设计将链接扫描分析的效率提高了100倍于传统的链接扫描仪器。质谱仪的关键部件是一种新型的高离子容量离子陷阱，它与四极碰撞池和四极质量分析器(即TRapqQ配置)串联在一起。这种离子捕捉器可以存储&gt；106离子，而不会显著降低其性能。对于8004000 m/z范围内的离子，当前陷阱的质量分辨率为全宽的一半，分辨率为100450，为在任何给定时间喷射到碰撞池中的离子提供了1020m/z的选择窗口。质谱仪用于检测多肽的灵敏度在低飞摩尔范围内。我们可以设想对该仪器进行相对直截了当的修改，以提高其分辨率和灵敏度。我们测试了串联质谱仪，以收集陷阱中存储的所有离子的前驱体离子光谱，并证明我们可以选择性地检测到非磷酸化多肽混合物中的磷酸多肽。基于这个原型仪器，我们计划构建一个功能齐全的质谱仪模型，用于快速和灵敏地检测蛋白质的修饰位点和丰度。 目前，我们正在制造第二代仪器，并对其进行改进，使其能够与正交飞行时间分析仪耦合，以准确地读出母离子和碎片离子的质量。

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 making a second generation instrument with improvements that will allow its coupling to an orthogonal time-of-flight analyzer for accurate mass readout of both the parent and fragment ions.