Ultrafast Differential Ion Mobility Spectrometry at Extreme Electric Fields in Multichannel Microchips

Ultrafast differential ion mobility spectrometry at extreme electric fields coupled to mass spectrometry.

Microchip-based field asymmetric waveform ion mobility spectrometry (FAIMS) analyzers featuring a grid of 35 mum-wide channels have allowed electric field intensity (E) over 60 kV/cm, or about twice that in previous devices with >0.5 mm gaps. Since the separation speed scales as E4 to E6, these chips filter ions in just approximately 20 micros (or approximately 100-10,000 times faster than "mac...

Protein analyses using differential ion mobility microchips with mass spectrometry.

Differential ion mobility spectrometry (FAIMS) integrated with mass spectrometry (MS) is a powerful new tool for biological and environmental analyses. Large proteins occupy regions of FAIMS spectra distinct from peptides, lipids, or other medium-size biomolecules, likely because strong electric fields align huge dipoles common to macroions. Here we confirm this phenomenon in separations of pro...

Differential ion mobility separations in up to 100% helium using microchips.

The performance of differential IMS (FAIMS) analyzers is much enhanced by gases comprising He, especially He/N2 mixtures. However, electrical breakdown has limited the He fraction to ~50%-75%, depending on the field strength. By the Paschen law, the threshold field for breakdown increases at shorter distances. This allows FAIMS using chips with microscopic channels to utilize much stronger fiel...

Ion Mobility Mass Spectrometry

for more complex analysers for automated sample processing and plant control. The separation time will continue to decrease; in the past there has been limited interest in fast separations but this could change as automated sample processing is developed. Increasing use of coupled techniques such as GC-GC, liquid chromatography-GC, and supercritical Suid chromatography-GC for the separation of ...

Ion Mobility-Mass Spectrometry