A number of peptides were studied with electrospray ionization--ion mobility spectrometry/mass spectrometry (ESI-IMS/MS). The ion mobility data were used to calculate the average collision cross sections of the different detected peptide ions in the nitrogen drift gas. By comparing the cross sections of related ions, structural information about the most probable location of the charge and the ...

High field asymmetric waveform ion mobility spectrometry (FAIMS), also known as differential ion mobility spectrometry, is emerging as a tool for biomolecular analysis. In this article, the benefits and limitations of FAIMS for protein analysis are discussed. The principles and mechanisms of FAIMS separation of ions are described, and the differences between FAIMS and conventional ion mobility ...

A secondary electrospray ionization (SESI) method was developed as a nonradioactive ionization source for ion mobility spectrometry (IMS). This SESI method relied on the gas-phase interaction between charged particles created by electrospray ionization (ESI) and neutral gaseous sample molecules. Mass spectrometry (MS) was used as the detection method after ion mobility separation for ion identi...

Ion mobility spectrometry is a well-known technique for analyzing gases. Examples are military applications, but also safety related applications, for example, for protection of employees in industries working with hazardous gases. In the last 15 years, this technique has been further developed as a tool for structural analysis, for example, in pharmaceutical applications. In particular, the co...

Detailed tropospheric ion measurements are needed to improve understanding of the electrical microphysics affecting clouds. Additionally, atmospheric ion mobility spectra can be used to identify ion growth processes leading to condensation nucleus formation. However these measurements are rare, particularly in the troposphere where the majority of clouds form. Developments in the operating theo...

"Why are we interested in ion mobility?" Ion mobility is not a new technique, but its recent marriage with high-resolution mass spectrometry on a commercial platform has made it possible to combine its separation and characterization capabilities with the power of MS and MS/MS data – the determination of size and shape as well as mass and charge. We are now seeing a rapid growth of applications...

A novel ion mobility spectrometry instrument incorporating a cyclotron geometry drift tube is presented. The drift tube consists of eight regions, four curved drift tubes and four ion funnels. Packets of ions are propagated around the drift tube by changing the drift field at a frequency that is resonant with the ion's drift time through each region. The approach trims each packet of ions as it...

Although nonnative protein conformations, including intermediates along the folding pathway and kinetically trapped misfolded species that disfavor the native state, are rarely isolated in the solution phase, they are often stable in the gas phase, where macromolecular ions from electrospray ionization can exist in varying charge states. Differences in the structures of nonnative conformations ...

tion for contact effects and of the small difference between NH3 and air mobilities. It points, however, in the same direction as the NH3-air work; namely, to a preferential change in concentration of NH3 molecules in the neighborhood of both ions. This effect is noticeable even at high concentrations of NH3. One thus sees in the negative ion the effect of the dielectric constant of NH3 on the ...

Aberrant glycosylation of human glycoproteins is related to various physiological states, including the onset of diseases such as cancer. Consequently, the search for glycans that could be markers of diseases or targets of therapeutic drugs has been intensive. Here, we describe a high-throughput ion mobility spectrometry/mass spectrometry analysis of N-linked glycans from human serum. Distribut...