Enhancements in travelling wave ion mobility resolution

Area of Science:

• Analytical Chemistry
• Biophysical Chemistry
• Structural Biology

Background:

• Ion mobility separation provides crucial gas-phase ion structural information via collision cross-section (CCS) determination.
• Travelling-wave ion mobility (TWIM) integrated into mass spectrometry enables routine CCS measurements.
• Physiologically relevant concentrations and diverse ionic species can be analyzed.

Purpose of the Study:

• To discuss technical advancements in second-generation travelling-wave ion mobility (TWIM) separators.
• To evaluate the impact of these improvements on mobility resolution.
• To demonstrate the utility of enhanced TWIM-MS for CCS measurements across various molecular sizes.

Main Methods:

• Utilized a second-generation travelling-wave ion mobility separator coupled with quadrupole/time-of-flight mass spectrometry.
• Measured collision cross-sections for peptides, anticancer drugs, a modified protein, and a large protein complex (GroEL).
• Compared CCS values obtained with the new separator against previous generation and theoretical data.

Main Results:

• Achieved up to a four-fold increase in mobility resolution compared to the previous generation.
• Successfully measured CCS for molecules ranging from small drugs (427 Da) to large complexes (802 kDa).
• Demonstrated excellent correlation between CCS values from the second-generation separator, the first-generation, and theoretical predictions.

Conclusions:

• The enhanced TWIM separator offers significantly improved performance for CCS measurements.
• This advancement facilitates more accurate structural characterization of a wide range of molecules.
• The technology supports routine structural analysis in fields like proteomics and drug discovery.