The initial ion velocity and its dependence on matrix, analyte and preparation method in ultraviolet matrix‐assisted laser desorption/ionization

Since the early days of matrix-assisted laser desorption/ionization (MALDI), measurements showing that MALDI ions and neutrals have high initial velocities have led to wide acceptance of the idea that a jet of released material entrains analyte ions. The initial velocity, which could previously be determined only with large uncertainty, can be measured today with high reliability in a delayed-extraction MALDI/time-of-flight system by following the linear dependence of ion flight time vs the applied extraction delay. The detection of different initial velocities for different matrices, with and without additives, for various preparation protocols and for different classes of analytes proves that the magnitude of the initial velocity can indeed be regarded as a valuable and meaningful characteristic of the MALDI process. Based on the results reported here, it is postulated that a high initial velocity results from incorporation of the analyte into the matrix crystals and that cooling upon expansion is effective at high initial velocities and responsible for reduced fragmentation observed in such cases compared with ‘slow’ matrices. Copyright © 1999 John Wiley & Sons, Ltd.

[1]  V. Horneffer,et al.  Investigations of 2,5-DHB and succinic acid as matrices for UV and IR MALDI. Part II: Crystallographic and mass spectrometric analysis , 1997 .

[2]  R. Levine,et al.  Homogeneous bottleneck model of matrix‐assisted ultraviolet laser desorption of large molecules , 1990 .

[3]  D. Allwood,et al.  UV Optical Absorption of Matrices Used for Matrix‐assisted Laser Desorption/Ionization , 1996 .

[4]  R. Cooks,et al.  Molecular secondary ion mass spectrometry. , 1980, Analytical chemistry.

[5]  Klaus Dreisewerd,et al.  Influence of the laser intensity and spot size on the desorption of molecules and ions in matrix-assisted laser desorption/ionization with a uniform beam profile , 1995 .

[6]  B. Spengler,et al.  Ultraviolet laser desorption/ionization mass spectrometry of proteins above 100,000 daltons by pulsed ion extraction time-of-flight analysis. , 1990, Analytical chemistry.

[7]  M. Karas,et al.  Factors affecting the resolution in matrix-assisted laser desorption--ionization mass spectrometry , 1994 .

[8]  M. Karas,et al.  Influence of the wavelength in high-irradiance ultraviolet laser desorption mass spectrometry of organic molecules , 1985 .

[9]  R. Srinivasan,et al.  Laser ablation of organic polymers: Microscopic models for photochemical and thermal processes , 1985 .

[10]  Y. Umezawa,et al.  Enhancement of uphill transport by a double carrier membrane system. , 1988, Analytical chemistry.

[11]  B. Spengler.  Post-source decay analysis in matrix-assisted laser desorption/ionization mass spectrometry of biomolecules† , 1997 .

[12]  R. Edmondson,et al.  High-resolution Mass Spectrometry and Accurate Mass Measurements with Emphasis on the Characterization of Peptides and Proteins by Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry , 1997 .

[13]  R. Beavis,et al.  Energetics of gramicidin S after UV laser desorption from a ferulic acid matrix , 1991 .

[14]  Ronald Beavis,et al.  Velocity distributions of intact high mass polypeptide molecule ions produced by matrix assisted laser desorption , 1991 .

[15]  C. Wilkins,et al.  Ultrahigh resolution matrix-assisted laser desorption/ionization of small proteins by Fourier transform mass spectrometry. , 1993, Analytical chemistry.

[16]  W. Ens,et al.  Kinetic energy measurements of molecular ions ejected into an electric field by matrix-assisted laser desorption. , 1992, Rapid communications in mass spectrometry : RCM.

[17]  W. Ens,et al.  ORTHOGONAL INJECTION OF MATRIX-ASSISTED LASER DESORPTION/IONIZATION IONS INTO A TIME-OF-FLIGHT SPECTROMETER THROUGH A COLLISIONAL DAMPING INTERFACE , 1998 .

[18]  R. Levine,et al.  Sublimation versus fragmentation in matrix-assisted laser desorption , 1990 .

[19]  L. Friedman,et al.  Rapid heating in fragile molecule mass spectrometry , 1987 .

[20]  Josef Michl,et al.  Secondary ion mass spectrometry of low-temperature solids , 1983 .

[21]  B. Chait,et al.  Direct comparison of infrared and ultraviolet wavelength matrix-assisted laser desorption/ionization mass spectrometry of proteins , 1998, Journal of the American Society for Mass Spectrometry.

[22]  M. Karas,et al.  Matrix-assisted ultraviolet laser desorption of non-volatile compounds , 1987 .

[23]  M. Karas,et al.  Delayed extraction time-of-flight MALDI mass spectrometry of proteins above 25,000 Da. , 1997, Journal of mass spectrometry : JMS.

[24]  Stephen A. Martin,et al.  Delayed extraction matrix‐assisted laser desorption time‐of‐flight mass spectrometry , 1995 .

[25]  B. Spengler,et al.  Angular and time resolved intensity distributions of laser-desorbed matrix ions , 1993 .

[26]  M. Karas,et al.  Laser desorption ionization of proteins with molecular masses exceeding 10,000 daltons. , 1988, Analytical chemistry.

[27]  M. Vestal,et al.  Applications of delayed extraction matrix-assisted laser desorption ionization time-of-flight mass spectrometry to oligonucleotide analysis. , 1996, Analytical chemistry.

[28]  R. S. Brown,et al.  Mass resolution improvement by incorporation of pulsed ion extraction in a matrix-assisted laser desorption/ionization linear time-of-flight mass spectrometer. , 1995, Analytical chemistry.

[29]  James P. Reilly,et al.  Improving the resolution of matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry by exploiting the correlation between ion position and velocity , 1994 .

[30]  W. Ens,et al.  Laser-pulse ejection of organic molecules from a matrix : lessons from fast-ion-induced ejection , 1991 .

[31]  J. A. Carroll,et al.  Near-ultraviolet-induced matrix-assisted laser desorption/ionization as a function of wavelength , 1998 .

[32]  Stephen A. Martin,et al.  On the initial velocity of ions generated by matrix-assisted laser desorption ionization and its effect on the calibration of delayed extraction time-of-flight mass spectra , 1997 .

[33]  Michael Karas,et al.  Matrix Dependence of Metastable Fragmentation of Glycoproteins in MALDI TOF Mass Spectrometry , 1995 .

[34]  W. Ens,et al.  Properties of matrix-assisted laser desorption. Measurements with a time-to-digital converter. , 1991, Rapid communications in mass spectrometry : RCM.

[35]  E. Nordhoff,et al.  Matrix‐assisted laser desorption/ionization mass spectrometry with additives to 2,5‐dihydroxybenzoic acid , 1993 .

[36]  T. Shaler,et al.  Time-of-flight mass spectrometry of underivatized single-stranded DNA oligomers by matrix-assisted laser desorption. , 1994, Analytical chemistry.

[37]  Marvin L. Vestal,et al.  Resolution and mass accuracy in matrix-assisted laser desorption ionization-time-of-flight , 1998 .

[38]  U. Pieles,et al.  Matrix-assisted laser desorption ionization time-of-flight mass spectrometry: a powerful tool for the mass and sequence analysis of natural and modified oligonucleotides. , 1993, Nucleic acids research.

[39]  F Hillenkamp,et al.  Infrared MALDI mass spectrometry of large nucleic acids. , 1998, Science.

[40]  L. Zhigilei,et al.  Velocity distributions of analyte molecules in matrix-assisted laser desorption from computer simulations , 1998 .

[41]  B. Spengler,et al.  Postionization of Laser-Desorbed Organic and Inorganic Compounds in a Time of Flight Mass Spectrometer , 1988 .

[42]  L. Zhigilei,et al.  On the threshold behavior in laser ablation of organic solids , 1997 .

[43]  J. Stults,et al.  Tryptic mapping of recombinant proteins by matrix-assisted laser desorption/ionization mass spectrometry. , 1993, Analytical chemistry.

[44]  J. Sunner,et al.  Mechanism of formation of FAB spectra , 1988 .