Investigation of the dynamics of matrix-assisted laser desorption/ionization ion formation using an electrostatic analyzer/time-of-flight mass spectrometer

Kinsel, Gary R.; Gimon-Kinsel, Mary E.; Gillig, Kent J.; Russell, David H.

doi:10.1002/(sici)1096-9888(199906)34:6<684::aid-jms822>3.0.co;2-o

Cited by 38 publications

(46 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Experimental evidence for entrainment, late ion release and analyte embedding in clusters has been available for some time, [56,57,74] and cluster-based models followed soon after. [3,17] Massive clusters of analyte ions with matrix have been suggested, up to 50 000 Da and more, [18] and various pathways for their decay into observable analyte ions suggested.…”

Section: Discussionsupporting

confidence: 88%

“…Clearly these assumptions are not valid for large parts of the plume, and ion energy deficits corresponding to late ion release have been measured in detail. [56,57] Without going into the complications arising from the numerous measurement and analysis methods used, the present results appear to be consistent with several ion velocity observations: the earliest matrix ions are faster than analyte ions, peak velocities increase somewhat with fluence, analyte ions may be entrained and/or be embedded in clusters for long periods after the laser pulse, and larger quantities of slower ions are generated at higher fluences.…”

Section: Discussionmentioning

confidence: 98%

“…Because no free analytes are found here, the question of single or dual kinetic domains for analyte ion formation cannot yet be addressed. [56,57] How clustering and desolvation depend on analyte size also remains to be investigated.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Special Feature: Tutorial

2011

J. Mass Spectrom.

View full text Add to dashboard Cite

Molecular dynamics simulations of matrix-assisted laser desorption/ionization were carried out to investigate laser pulse width and fluence effects on primary and secondary ionization process. At the same fluence, short (35 or 350 ps) pulses lead to much higher initial pressures and ion concentrations than longer ones (3 ns), but these differences do not persist because the system relaxes toward local thermal equilibrium on a nanosecond timescale. Higher fluences accentuate the initial disparities, but downstream differences are not substantial. Axial velocities of ions and neutrals are found to span a wide range, and be fluence dependent. Total ion yield is only weakly dependent on pulse width, and consistent with experimental estimates. Secondary reactions of matrix cations with analyte neutrals are efficient even though analyte ions are ablated in clusters of matrix.

show abstract

Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 98%

See 1 more Smart Citation

Special Feature: Tutorial

2011

J. Mass Spectrom.

View full text Add to dashboard Cite

show abstract

“…Hereafter, we use the term droplets to mean all but small numbers of molten or solid matrix molecules, in which case we will use the term clusters. Hillenkamp, in discussions with John Fenn, suggested the possibility that MALDI and ESI might have similar mechanistic origins [32], but the first experimental evidence for clusters in MALDI were published by Kinsel et al [33]. To explain results obtained studying the dynamics of ionization in MALDI, these authors proposed three possible scenarios, one involving emission of ions from clusters in a process analogous to ESI.…”

Section: The Cluster Mechanism In Maldimentioning

confidence: 99%

“…As noted above, it is well recognized that the cluster model is potentially related to ESI [3,8,32,33] and, thus, multiple charging of clusters may be a possible outcome. However, Vestal's unified ionization model proposed in 1983, based on a charged droplet/cluster model, encompasses fast atom bombardment (FAB), secondary ion mass spectrometry (SIMS), laser desorption (LD), field desorption (FD), and thermospray ionization (TSI), all methods that produce abundant singly charged ions [29].…”

Section: The Cluster Mechanism In Maldimentioning

confidence: 99%

A Mechanism for Ionization of Nonvolatile Compounds in Mass Spectrometry: Considerations from MALDI and Inlet Ionization

Trimpin

Wang

Inutan

et al. 2012

J. Am. Soc. Mass Spectrom.

113

530

View full text Add to dashboard Cite

Mechanistic arguments relative to matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) address observations that predominately singly charged ions are detected. However, recently a matrix assisted laser ablation method, laserspray ionization (LSI), was introduced that can use the same sample preparation and laser as MALDI, but produce highly charged ions from proteins. In MALDI, ions are generated from neutral molecules by the photon energy provided to a matrix, while in LSI ions are produced inside a heated inlet tube linking atmospheric pressure and the first vacuum region of the mass spectrometer. Some LSI matrices also produce highly charged ions with MALDI ion sources operated at intermediate pressure or high vacuum. The operational similarity of LSI to MALDI, and the large difference in charge states observed by these methods, provides information of fundamental importance to proposed ionization mechanisms for LSI and MALDI. Here, we present data suggesting that the prompt and delayed ionization reported for vacuum MALDI are both fast processes relative to producing highly charged ions by LSI. The energy supplied to produce these charged clusters/droplets as well as their size and time available for desolvation are determining factors in the charge states of the ions observed. Further, charged droplets/clusters may be a common link for ionization of nonvolatile compounds by a variety of MS ionization methods, including MALDI and LSI.

show abstract

A comparative study of a liquid and a solid matrix in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and collision cross section measurements

Ring

Rudich

2000

Rapid Commun. Mass Spectrom.

View full text Add to dashboard Cite

We present experimental matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) results comparing a liquid (glycerol/K(4)[Fe(CN)(6)]) and a solid matrix (2,5-dihydroxybenzoic acid, DHB) with respect to analyte signal stability and initial ion velocity. For applications requiring stable production of analyte ions over a long period of time, the liquid matrix is superior to the solid matrix. The stable analyte ion signal obtained from a liquid matrix allowed the measurement of collision cross sections of small poly(ethylene glycol) (PEG(n)) adduct ions in the flight tube with good resolution. The initial velocity of these adduct ions was measured. It was found that analyte molecules from the liquid matrix have initial ion velocities significantly smaller than those from the solid matrix. MALDI-TOF measurements for large molecules using a liquid matrix are therefore likely to result in smaller systematic errors in mass calibrations due to initial ion velocity.

show abstract

Investigation of the dynamics of matrix-assisted laser desorption/ionization ion formation using an electrostatic analyzer/time-of-flight mass spectrometer

Cited by 38 publications

References 17 publications

Special Feature: Tutorial

Special Feature: Tutorial

A Mechanism for Ionization of Nonvolatile Compounds in Mass Spectrometry: Considerations from MALDI and Inlet Ionization

A comparative study of a liquid and a solid matrix in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and collision cross section measurements

Contact Info

Product

Resources

About