New frontiers for mass spectrometry based upon structures for lossless ion manipulations

Abstract

Structures for lossless ion manipulations (SLIM) provide a new paradigm for efficient, complex and extended gas phase ion manipulations. SLIM are created from electric fields generated by the application of DC and RF potentials to arrays of electrodes patterned on two parallel surfaces. The electric fields provide lossless ion manipulations, including effective ion transport and storage. SLIM modules have been developed using both constant and oscillatory electric fields (e.g. traveling waves) to affect the ion motion. Ion manipulations demonstrated to date with SLIM include: extended trapping, ion selection, ion dissociation, and ion mobility spectrometry (IMS) separations achieving unprecedented ultra high resolution. SLIM thus provide the basis for previously impractical manipulations, such as very long path length ion mobility separations where ions traverse a serpentine path multiple times, as well as new capabilities that extend the utility of these developments based on temporal and spatial compression of ion mobility separations and other ion distributions. The evolution of SLIM devices developed over the last three years is reviewed and we provide examples of various ion manipulations performed, and briefly discuss potential applications and new directions.

Recommendations for reporting ion mobility Mass Spectrometry measurements

“…The ions are subjected to varying E / N , with peak values reaching 50–160 Td (Giles et al, ; Gabelica & Marklund, ). Structures for lossless ion manipulation (SLIM) can be used to implement traveling waves (Tolmachev et al, ) and thus perform TWIMS separations (Deng et al, ; Ibrahim et al, ). –TIMS (trapped ion mobility spectrometry), in which ions are held in place against a moving gas with an electric field (Fernandez‐Lima et al, ). Multiple isomers/conformers are trapped simultaneously at different E values resulting from a voltage gradient applied across the IMS tunnel region.…”

Recent advances in lipid separations and structural elucidation using mass spectrometry combined with ion mobility spectrometry, ion-molecule reactions and fragmentation approaches

“…In the analyses, both platforms showed significantly better separations than the AP-DTIMS platform [30–33]. This enhanced resolution was due to the FAIMS device being constructed to operate at higher voltages than commercial versions [30] and the SLIM TWIMS platform having a compact serpentine ion drift path [31,32] which allowed ultrahigh resolution IMS separation to be achieved due to the long IMS path (30.6 m, in this example) [33]. A final IMS technique to note is the recently developed trapped ion mobility spectrometry (TIMS) method, which also allows high resolution IMS separations and shows promise for future lipidomic separations [34].…”

Reproducible workflow for multiplexed deep-scale proteome and phosphoproteome analysis of tumor tissues by liquid chromatography–mass spectrometry

“…This and other potential advantages of FAIMS in the context of proteomics experiments have been described 35 . In the future, devices such as SLIM (structures for lossless ion manipulations 36 ) may provide even higher sensitivity, resolution, and speed, as compared with current devices. Diminished co-isolation and increased sensitivity should also be achievable by increasing the chromatographic resolution of the online chromatography with longer columns, more efficient and uniform column packing, or use of smaller bead sizes to the extent the column back pressure can be handled by the LC pumping system.…”