Waters SELECT SERIES Cyclic IMS

Significance of the Topic

Ion mobility mass spectrometry combined with time of flight enables separation of ions by shape and mass offering deep insights into structure dynamics and composition of complex samples. The ability to conduct multiple mobility passes and fragmentation rounds addresses challenges in structural isomer differentiation and improves confidence in analytical results.

Objectives and Study Overview

The study introduces the SELECT SERIES Cyclic IMS a novel instrument that merges cyclic ion mobility separation with high performance time of flight mass spectrometry to expand experimental flexibility and achieve superior resolution. The aim is to demonstrate enhanced ion mobility resolution advanced IMSn capabilities and robust mass analysis.

Methodology and Instrumentation

A cyclic ion mobility device enables ions to recirculate multiple times increasing separation based on collision cross section differences. Customized IMSn experiments allow ion selection storage activation and multiple mobility separations for detailed structural interrogation. Key instrument components include

• A cyclic IMS path with pre and post array storage regions
• TWave Array for ion guiding and mobility control
• StepWave ion guide and quadrupole mass filter
• Helium cell for collisional cooling
• XS Transfer Device for ion transfer and trapping
• High performance time of flight analyzer with dual stage reflectron
• Air cooled turbomolecular and backing pumps

Key Results and Discussion

The instrument achieved mobility resolution improvements proportional to number of passes demonstrated by baseline separation of reverse sequence peptides SDGRG and GRGDS after one hundred passes. High resolution time of flight spectra exhibited resolving power above one hundred thousand full width at half maximum on the seven plus charge state of monomeric streptavidin. The combination of mobility based selection and fragmentation enabled detailed characterization of isomeric and conformational species.

Benefits and Practical Applications

• Enhanced confidence in structural assignments due to ultrahigh mobility resolution
• Flexible experimental designs supporting IMS IMS and IMSn workflows
• Improved sensitivity dynamic range and accurate mass measurement for complex samples
• Capability to probe gas phase interconversion and conformational dynamics

Future Trends and Opportunities

The modular design allows development of extended pass protocols and coupling with advanced fragmentation techniques to study larger biomolecular assemblies. Integration with machine learning driven data analysis promises to accelerate interpretation of complex datasets. Potential applications include detailed structural mapping of proteins nucleic acids and synthetic polymers in pharmaceutical environmental and clinical research.

Conclusion

The SELECT SERIES Cyclic IMS represents a versatile platform pushing the boundaries of ion mobility mass spectrometry. Its ability to conduct multiple mobility separations alongside high resolution mass analysis provides analytical chemists with a powerful tool for structural elucidation and complex mixture characterization.