Achieving High Resolution Ion Mobility Separations Using Traveling Waves in Compact Multiturn Structures for Lossless Ion Manipulations

Abstract

We report on ion mobility (IM) separations achievable using traveling waves (TW) in a Structures for Lossless Ion Manipulations (SLIM) module having a 44 cm path length and 16 90° turns. The performance of the TW-SLIM module was evaluated for ion transmission and IM separations with different RF, TW parameters, and SLIM surface gaps in conjunction with mass spectrometry. In this work, TWs were created by the transient and dynamic application of DC potentials. The module demonstrated highly robust performance and, even with 16 closely spaced turns, achieving IM resolution performance and ion transmission comparable to a similar straight path module. We found an IM peak capacity of ~31 and peak generation rate of 780 s−1 for TW speeds of ~80 m/s using the current multi-turn TW-SLIM module. The separations achieved for isomers of peptides and tetrasaccharides were found to be comparable to those from a ~0.9-m drift tube-based IM-MS platform operated at the same pressure (4 Torr). The combined attributes of flexible design, low voltage requirements and lossless ion transmission through multiple turns for the present TW-SLIM module provides a basis for SLIM devices capable of achieving much greater IM resolution via greatly extended ion path lengths and using compact serpentine designs.

Coming to Grips with Ambiguity: Ion Mobility-Mass Spectrometry for Protein Quaternary Structure Assignment

“…Although not discussed in detail here, it is also clear that increases in CCS precision will drive concomitant increases in the PPV of IM-MS restraints, as decreasing the current ± 3% CCS error value used in the analyses described here will surely reduce the occurrence of spurious structural families within a filtered structural ensemble. [63–65] On the other hand, our data demonstrate that much can be accomplished using current IM-MS capabilities and that the proper application of restraints can be used to build high-confidence models of multi-protein complexes with both full knowledge of their precisions and informed estimates of their accuracies.…”

Correlating Resolving Power, Resolution, and Collision Cross Section: Unifying Cross-Platform Assessment of Separation Efficiency in Ion Mobility Spectrometry

“…Separating these compounds based purely on mobility alone would require 280 resolving power or less, which is currently obtainable (Table S2). 30,57,61 To separate ca. 95% (CCS ≥ 0.02%) of the peptides by IM alone would require about 7,000 mobility resolving power.…”

Ion Mobility Collision Cross Section Compendium

“…Other ion mobility techniques including cyclic and extended path length traveling wave devices are currently in development. 8,9 This recent and unprecedented commercial accessibility of IM-MS in combination with existing liquid chromatography and tandem MS functionality has provided powerful multidimensional separation capabilities to the greater research community, 10–13 which in turn has broadened the scope of applications and fields in which IM-MS is now making a significant impact. 14–19 Many of the contemporary challenges being addressed by IM-MS are grand challenges of our era of humanity.…”