Electrodynamic Containment of Charged Particles

Wuerker, R. F.; Shelton, H.; Langmuir, R. V.

doi:10.1063/1.1735165

Cited by 634 publications

(288 citation statements)

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“…This data concurs with the observation by Wuerker et al that a particle array can be compressed towards the null point by increasing AC trap [25]. The BP was independent of AC trap because only the DC potentials were required to offset the force of gravity.…”

Section: Deposition/balance Potential Versus Ac Trapping Potential (Asupporting

confidence: 91%

Wall-less sample preparation of μm-sized sample spots for femtomole detection limits of proteins from liquid based UV-MALDI matrices

Bogan

Agnes

2004

J. Am. Soc. Mass Spectrom.

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Previously, we introduced wall-less sample preparation (WaSP), technology that involves the use of an electrodynamic balance (EDB) to prepare m-sized sample spots for analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). In that work we demonstrated the detection of femtomole quantities of a low molecular weight peptide and a hydrophobic ester (both Ͻ600 Da). Here we use WaSP to test the hypothesis that the use of small sample spot sizes and an instrument equipped with delayed extraction would increase the analytical utility of liquid sample spots for peptide and protein (Ͼ2500 Da) analysis by UV-MALDI-TOF-MS (Sze et al.; J. Am. Soc. Mass Spectrom. 1998, 9, 166 -174). To aid the optimization of preparing m-sized sample spots by WaSP, optical microscopy and mass spectrometry were used to investigate nonvolatile solute concentration effects on droplet fission and sample spot size, modifications of the EDB electric field to control droplet ejection, and the use of multiple droplet deposition to increase sample loading. Also described is a rapid deposition mode of operation for WaSP that allows single droplets generated at 1 Hz to be levitated briefly (ϳ500 ms) before being ejected autonomously and deposited as a concentrated sample spot with a spatial accuracy of Ϯ5 m. To test the sensitivity of the method, one hundred glycerol droplets (270 pL each, 27 nL total) each containing 32 amol lysozyme were deposited on top of each other one-at-a-time to create a single sample spot. Using a mass spectrometer equipped with delayed extraction to analyze this sample spot, we verified the hypothesis of Sze et al. by achieving detection limits three orders of magnitude below that previously observed for the detection of a protein by UV-MALDI-TOF-MS with a chemical-doped liquid matrix sample preparation. (J Am Soc Mass Spectrom 2004, 15, 486 -495)

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Section: Deposition/balance Potential Versus Ac Trapping Potential (Asupporting

confidence: 91%

Wall-less sample preparation of μm-sized sample spots for femtomole detection limits of proteins from liquid based UV-MALDI matrices

Bogan

Agnes

2004

J. Am. Soc. Mass Spectrom.

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“…In low-vacuum experiments such as the resonant CID reported here, both amplitude and energy dissipation resonances are significantly broadened [36 -38]. Therefore, calculating ␤ using eq 2 rather than a simpler [39], more commonly used approximation ␤ ϭ (a ϩ 0.5q 2 ) 0.5 , does not significantly improve the accuracy of calculating for CID experiments at a low q. On the other hand, approximation given by eq 2 becomes critical for the resonant ejection (directly related to radial amplitude resonance) experiments performed at lower pressures [40] and at q Ͼ 0.4.…”

Section: Resonant Excitation Waveforms and Circuitrymentioning

confidence: 99%

Establishing low-energy sequential decomposition pathways of leucine enkephalin and its N- and C-terminus fragments using multiple-resonance CID in quadrupolar ion guide

Rakov¹,

Borisov²,

Whitehouse³

2004

J. Am. Soc. Mass Spectrom.

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The simultaneous resonant low-energy excitation of leucine enkephalin and its fragment ions was demonstrated in a collision cell of the multipole-quadrupole time-of-flight instrument. Using low-amplitude multiple-resonance excitation CID, we were able to show the exclusive sequential fragmentation of N-and C-terminus fragments all the way to the final fragmentsimmonium ions of phenylalanine or tyrosine. In this CID mode the single-channel dissociation of each new generation of fragments followed the lowest energy decomposition pathways observable on the time scale of our experiment. Up to six generations of sequential dissociation were carried out in multiple-resonance CID experiments. The direct qualitative comparison of fragmentation of axial-acceleration versus resonant (radial) CID was performed in the same instrument. In both activation methods, fragmentation patterns suggested complex decomposition mechanisms attributable to dynamic competition between sequential and parallel dissociation channels. R esonant harmonic excitation of ions is the primary method for MS detection and activation of induced dissociation in most ion traps. Simultaneous excitation of ions of different m/z ratios is routinely employed to illuminate dissociation pathways using ion traps. It can also be used in harmonic ion guides in order to selectively eject or dissociate ions on their way to an MS analyzer. This paper reports results of validation of a nontrapping multiple frequency component low-energy resonant collision-induced dissociation (CID) in a linear quadrupole ion guide.Several of the ion activation methods used in modern MS instruments are selective, by nature, and target exclusively the parent ion, supplying no additional energy to its primary fragments. As examples of such methods, the sustained off-resonance irradiation (SORI) [1], or on-resonance CID in ion cyclotron resonance (ICR) cells [2] can be mentioned. Other activation methods, such as infrared multi-photon dissociation (IRMPD), and its variations [3,4], or black body infrared dissociation (BIRD) [5] are nonselective, by nature, and always excite primary fragments along with the parent ion. A vast majority of ion activation methods may excite primary fragments depending on the condition of the experiment. In such methods, modeling of the dissociation process can be quite complex. For example, in surface induced dissociation (SID) experiments with moderate impact energies, the dissociation event most likely comprises activation of only the parent ion at the surface, followed by its recoil and subsequent unimolecular decomposition. In contrast, at high impact energies, more extensive fragmentation can be observed due to on-surface shattering of the precursor and possibly some of its primary fragments [6].Axial CID in ion guides (or in triple-quadrupoles) achieved by accelerating the primary ions into the collision cell operated at an elevated pressure is a potentially nonselective activation technique. If initial collisions of the projectile ion with the backgr...

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“…The first crystal of charged particles was achieved for aluminum micro-particles which were cooled via buffer gas [5]. A major breakthrough was achieved thanks to the invention of laser cooling [6,7] and its successful implementation for trapped ions [8,9].…”

Section: Martin B Plenio and Alex Retzkermentioning

confidence: 99%

Ion Traps as a testbed of classical and quantum statistical mechanics

Plenio¹,

Retzker²

2013

Annalen der Physik

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The development of statistical mechanics over the last century represents a major advance in the Natural Sciences. It is capable of describing a wide range of phenomena including the properties of phase transitions by reducing the complexity of quantum-many-body systems to simple general principles rooted in statistical methods that hold true in macroscopic systems. These principles apply to a broad range of physical theories, encompassing phenomena that are for example governed by classical, relativistic or quantum physics. While many of these predictions have been confirmed experimentally, the exploration, under highly controlled conditions, of the statistical mechanics of mesoscopic systems and the theoretical prediction of their behavior does still represent a challenge for both theory and experiment. A new avenue towards the controlled exploration of the classical and quantum statistical mechanics of mesoscopic systems has opened up

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Electrodynamic Containment of Charged Particles

Cited by 634 publications

References 1 publication

Wall-less sample preparation of μm-sized sample spots for femtomole detection limits of proteins from liquid based UV-MALDI matrices

Wall-less sample preparation of μm-sized sample spots for femtomole detection limits of proteins from liquid based UV-MALDI matrices

Establishing low-energy sequential decomposition pathways of leucine enkephalin and its N- and C-terminus fragments using multiple-resonance CID in quadrupolar ion guide

Ion Traps as a testbed of classical and quantum statistical mechanics

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