A new method for enhancing peptide ion identification in proteomics analyses using ion mobility data is presented. Ideally, direct comparisons of experimental drift times (t(D)) with a standard mobility database could be used to rank candidate peptide sequence assignments. Such a database would represent only a fraction of sequences in protein databases and significant difficulties associated w...

We evaluated 11 air ion spectrometers from Airel Ltd. after they had spent one year in field measurements as a part of the EUCAARI project: 5 Air Ion Spectrometers (AIS), 5 Neutral cluster and Air Ion Spectrometers (NAIS) and one Airborne NAIS (ANAIS). This is the first time that an ANAIS is evaluated and compared so extensively. The ion spectrometers’ mobility and concentration accuracy was ev...

Carbohydrates play numerous critical roles in biological systems. Characterization of oligosaccharide structures is essential to a complete understanding of their functions in biological processes; nevertheless, their structural determination remains challenging in part due to isomerism. Ion mobility spectrometry provides the means to resolve gas phase ions on the basis of their shape-to-charge...

The effects of fluorine ion bombardment on the channel transport properties of AlGaN /GaN heterostructures have been investigated. Ion bombardment of the heterostructure was carried out within a CF4 plasma in a reactive ion etching system at various self-bias voltages. Hall mobility and sheet electron concentration for the two-dimensional electron gas showed strong dependence on bombardment dur...

Results from ion mobility studies of tryptic peptides suggest that, in some cases, the gas-phase structures can be related to the solution-phase structure of the parent protein. The interpretation of ion mobility measurements is supported by results from molecular modeling and H/D exchange experiments on the same peptides. This study clearly illustrates the utility of IM-MS for screening comple...

Injected-ion mobility/mass spectrometry techniques have been used to measure the reduced ion mobilities for negatively charged raffinose, melezitose and α-, β-, and γ-cyclodextrins formed by electrospray ionization. At low injection energies, the mass spectra are dominated by negatively charged (deprotonated) parent ions. At high injection energies, the mass spectra recorded for the cyclodextri...

The use of different drift gases to alter separation factors (alpha) in ion mobility spectrometry has been demonstrated. The mobility of a series of low molecular weight compounds and three small peptides was determined in four different drift gases. The drift gases chosen were helium, argon, nitrogen, and carbon dioxide. These drift gases provide a range of polarizabilities and molecular weigh...

This manuscript presents our initial results and development of a novel hybrid instrument that combines atmospheric pressure ion mobility spectrometry (AP-IMS) with Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Our preliminary results obtained from atmospheric pressure mobility separation of peptide mixtures combined with high-resolution FTICR mass analysis are demonst...

This study reports on the use of traveling wave ion mobility quadrupole time-of-flight (ToF) mass spectrometry for plasma metabolomics. Plasma metabolite profiles of obese Zucker fa/fa rats were obtained after the administration of different oral doses of Xanthohumol; a hop-derived dietary supplement. Liquid chromatography coupled data independent tandem mass spectrometry (LC-MSE) and LC-ion mo...

The first application of a novel differential mobility analyzer, the radial opposed migration ion and aerosol classifier (ROMIAC), is demonstrated. The ROMIAC uses antiparallel forces from an electric field and a cross-flow gas to both scan ion mobilities and continuously transmit target mobility ions with 100% duty cycle. In the ROMIAC, diffusive losses are minimized, and resolution of ions, w...