Kurulugama Ruwan T, Nachtigall Fabiane M, Lee Sunyoung, Valentine Stephen J, Clemmer David E
Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA.
J Am Soc Mass Spectrom. 2009 May;20(5):729-37. doi: 10.1016/j.jasms.2008.11.022. Epub 2008 Dec 6.
A new method that allows a linear drift tube to be operated as a continuous ion mobility filter is described. Unlike conventional ion mobility instruments that use an electrostatic gate to introduce a packet of ions into a drift region, the present approach uses multiple segmented drift regions with modulated drift fields to produce conditions that allow only ions with appropriate mobilities to pass through the instrument. In this way, the instrument acts as a mobility filter for continuous ion sources. By changing the frequency of the applied drift fields it is possible to tune this instrument to transmit ions having different mobilities. A scan over a wide range of drift field frequencies for a single ion species shows a peak corresponding to the expected resonance time of the ions in one drift region segment and a series of peaks at higher frequencies that are overtones of the resonant frequency. The measured resolving power increases for higher overtones, making it possible to resolve structures that were unresolved in the region of the fundamental frequency. We demonstrate the approach by examining oligosaccharide isomers, raffinose and melezitose as well as a mixture of peptides obtained from enzymatic digestion of myoglobin.
本文描述了一种能使线性漂移管作为连续离子迁移率过滤器运行的新方法。与使用静电门将离子包引入漂移区的传统离子迁移率仪器不同，本方法采用多个带有调制漂移场的分段漂移区，以产生仅允许具有适当迁移率的离子通过仪器的条件。通过这种方式，该仪器可作为连续离子源的迁移率过滤器。通过改变所施加漂移场的频率，可以调整该仪器以传输具有不同迁移率的离子。对单一离子种类在宽范围的漂移场频率上进行扫描，会显示出一个对应于离子在一个漂移区段中预期共振时间的峰，以及在更高频率处的一系列作为共振频率泛音的峰。对于更高的泛音，测量得到的分辨率会增加，从而有可能分辨在基频区域未分辨的结构。我们通过研究低聚糖异构体、棉子糖和松三糖以及从肌红蛋白酶解获得的肽混合物来演示该方法。
