Ion Mobility Spectrometer with Radial Collisional Focusing

Guo, Yuzhu; Wang, Jiaxi; Javahery, Gholamreza; Thomson, Bruce A.; Siu, Kin Wai Michael

doi:10.1021/ac048974n

Cited by 49 publications

(68 citation statements)

References 55 publications

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“…The peak widths of the distributions are wider than the width of a peak in which band-broadening is attributable solely to diffusion (simulated distributions based only on diffusion are shown as dash lines) [1]. As previously observed, the possibility exists that one or both of these distributions may contain unresolved conformations (of similar cross-sections) [7]. By contrast, the [Cd 7 MT2A ϩ 4H] 4ϩ ion has apparently only one distinct conformation at 745 Å 2 .…”

Section: Cd-and Zn-mt2a Complexesmentioning

confidence: 61%

“…Details of this instrument have been published [7]. Briefly, Q1 and Q3 are conventional MS analyzers; however, the q2 is a 20-segment quadrupole/ion-mobility cell and is physically isolated in its own chamber from the Q1 and Q3 chambers that are at much lower pressure ( Figure 1).…”

Section: Instrumentationmentioning

confidence: 99%

“…Figure 2b and c display relevant windows of the arrival-time distributions (ion-mobility spectra) in units of crosssection [1,2,7] for different charge states of the Cd 7 MT2A complex and apoMT2A. The [Cd 7 MT2A ϩ 3H] 3ϩ ion exhibits two distinct distributions at 610 and 755 Å 2 .…”

Section: Cd-and Zn-mt2a Complexesmentioning

confidence: 99%

“…This combination typically results in modest sensitivity. Recently, we reported construction and testing of an ion-mobility spectrometer that has its mobility cell as a 20-segment rf-only quadrupole and functionally the second quadrupole (q2) of a triple-quadrupole mass spectrometer [7]. The characteristics of high cell pressure (maximum of 4 torr of helium) and low axial field (20 -160 V/20.2 cm) meant that there was negligible internal excitation of the ions, despite applications of rf and axial fields.…”

mentioning

confidence: 99%

“…In addition, the presence of collisional focusing ensured efficient ion transmission and good sensitivity. Indeed, most measurements were made with solutions containing 10 M peptides and proteins [7], concentrations typical of electrospray experiments.…”

mentioning

confidence: 99%

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Combined ion-mobility and mass-spectrometry investigations of metallothionein complexes using a tandem mass spectrometer with a segmented second quadrupole

Guo

Ling

Thomson

et al. 2005

J. Am. Soc. Mass Spectrom.

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Rabbit metallothionein (MT) 2A complexes with Cd(II), Zn(II), Ag(I), Cu(I), Hg(II), arsenite, monomethylarsonous acid (MMA), and dimethylarsinous acid (DMA) have been examined using ion-mobility measurements and mass spectrometry in a triple-quadrupole mass spectrometer equipped with a segmented second quadrupole that doubled as an ion-mobility cell [Guo, Y.; Wang, J.; Javahery, G.; Thomson, B. A.; Siu, K. W. M. An Ion-Mobility Spectrometer with Radial Collisional Focusing. Anal. Chem. 2005, 77, 266 -275]. The metal ions confer conformational rigidity on the MT complexes, which counteracts Coulombic repulsion among protons added as a result of electrospray. Triply and quadruply protonated Cd 7 MT2A have smaller cross-sections than the Cd 7 MT2A structure deduced from published NMR data. For the 6ϩ ions, the As 6 MT2A complex has a cross-section of 790 Å 2 ; the MMA 10 MT2A complex, 920 Å 2 ; and the DMA 20 MT2A complex, 1220 Å 2 . This increase in cross-section of the As(III) species, from As 3ϩ to MMA to DMA, is interpreted as a consequence of decreasing multiple coordination and increasing number of methyl groups. I on mobility, K, is a measure of the ion's effective size by virtue of its collision cross-section, ⍀ T , at temperature T, with a given buffer gas, typically helium, under the influence of a weak electric field. Provided that the number density of the buffer gas, N, is sufficiently high and the imposed electric field, E, is sufficiently low, the drift velocity, v d , is proportional to E with K being the proportionality constant.⍀ T can be determined from K using the Mason-Schamp equation [1, 2]:where z is the numerical charge, e is the elementary charge, is the reduced mass of the ion and helium, and k is the Boltzmann's constant.The collision cross-section of an ion is one of the most readily measurable, albeit somewhat crude, structure-related parameter that has come under close scrutiny in the last decade or so. Coupled to comparisons with theoretical cross-sections calculated from probable structures found by optimizations using molecular dynamics and first-principle methods, measurements of ⍀ T have allowed insights into three-dimensional structures of peptides and proteins in the gas-phase [3][4][5].Ion-mobility measurements are typically made in drift tubes at atmospheric or subatmospheric pressure containing a stack of ring electrodes which maintain a constant electric field in the axial direction [6]. Highresolution operation requires the use of high (nearatmospheric) pressure and high voltages; the need for high pressure in the drift tube necessitates the use of small apertures in interfacing with the mass-analyzer region of the spectrometer (which requires lowpressure operation) and leads to radial diffusion because of increased ion residence time. This combination typically results in modest sensitivity. Recently, we reported construction and testing of an ion-mobility spectrometer that has its mobility cell as a 20-segment rf-only quadrupole and functionally the second quadrupole (q2)...

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Section: Cd-and Zn-mt2a Complexesmentioning

confidence: 61%

Section: Instrumentationmentioning

confidence: 99%

Section: Cd-and Zn-mt2a Complexesmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Combined ion-mobility and mass-spectrometry investigations of metallothionein complexes using a tandem mass spectrometer with a segmented second quadrupole

Guo

Ling

Thomson

et al. 2005

J. Am. Soc. Mass Spectrom.

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Multidimensional Separations by Ion Mobility‐Mass Spectrometry

Hines

Enders

McLean

2012

Encyclopedia of Analytical Chemistry

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Ion mobility‐mass spectrometry (IM‐MS) couples gas‐phase structural separations by IM with mass‐to‐charge separations by MS. The utility of this integration of multidimensional separation dimensions is manifold, including (i) high throughput multidimensional separations, (ii) separation of chemical noise, and (iii) rapid information in structural biology. This article introduces the unique advantages of IM‐MS in biological fields ranging from systems biology to structural biology, the context of which is introduced by a historical perspective of key advances accomplished over the last century. Contemporary and emerging technology for performing IM‐MS is presented, and applications using conformational data sets in proteomics, glycomics, and lipidomics are described.

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