Angle-resolved Mass Spectrometry Research Articles

Gas phase copper(I) ion affinities of valine, lysine, and arginine based on the dissociation of Cu +-bound heterodimers at varying internal energies

The Cu + affinities of the amino acids valine (Val), lysine (Lys), and arginine (Arg) are determined in the gas phase based on the dissociations of Cu +-bound dimers [A + B i ]Cu +, in which A represents one of the three amino acids studied and B i a set of different amino acids of known Cu + affinity (kinetic method). In order to deconvolute entropic contributions from experimentally measured free energies, the decompositions of [A + B i ]Cu + are assessed as a function of internal energy using angle-resolved mass spectrometry. The Cu + affinities deduced for Val, Lys, and Arg are 283, 355, and 364 kJ mol −1, respectively. Lysine and arginine are found to have substantially larger entropies of Cu + attachment when compared to valine. The combined affinity and entropy data are consistent with participation of the flexible side chain substituents of lysine and arginine in the coordination of Cu +, yielding multidentate complexes of markedly higher stability than the aliphatic amino acid valine.

Angle-resolved mass spectrometry of chloromethanes in an intense laser field

Angle-resolved mass spectrometry of tetrachloromethane, trichloromethane and dichloromethane irradiated by intense laser light has been carried out using a quadrupole mass spectrometer. Ionization was by means of very intense, short-duration, linearly polarized laser pulses whose wavelength, pulse duration and intensity were, respectively, 532 nm, 35 ps and 2–8 × 1013 W cm−2. The laser-induced fragmentation pattern was found to be dramatically different from that obtained using conventional mass spectrometric methods with 70 eV electrons. A degree of ion selectivity can be obtained by judicious choice of laser parameters. The direction of the laser's polarization vector with respect to the mass spectrometer's axis is found to be one such important parameter which dramatically affects the morphology of the fragmentation pattern. © 1998 John Wiley & Sons, Ltd.

Angle Resolved Mass Spectrometry of Positive Ions Transmitted through High Aspect Ratio Channels in a Radio Frequency Discharge

The behavior of positive ions in high aspect ratio structures, relevant to the reactive ion etching of deep trenches, has been studied by means of energy resolved mass spectrometry. High aspect ratio trenches are simulated by capillary plates with various aspect ratios. Angle resolved measurements of the ion current passing through the channels in the capillary plates have been performed in low pressure argon and helium radio frequency plasmas. The angular distribution of the ion counts becomes strongly anisotropic after the ions have passed through the channels. The narrowing of the ion distribution with increasing aspect ratio is explained by the loss of ions at the side walls of the channel. This loss is mainly a consequence of geometrical shadowing; ion loss due to deflection by surface charge on the capillary plates has only little effect at moderate power inputs. At high power inputs ion losses become extremely high, so the transmission through the channel plate decreases almost to zero.

Collision spectroscopy in isomer characterization: The case of (E)- and (Z)-p-nitrophenyldiazotert-butyl sulphides

The structural characterization of the E and Z isomers of p-nitrophenyl-diazo tert-butyl sulphide has been achieved by means of different ionization methods (electron impact, fast atom bombardment, positive-ion chemical ionization) and collision experiments performed under different kinetic energy regimes (high- and low-energy collisions, angle-resolved mass spectrometry and energy-resolved mass spectrometry). The two compounds give rise to identical fragmentation patterns. Collision experiments, both at low energy and in the keV range at a scattering angle of 0°, in M+· species obtained by electron impact on the two isomers, do not show any significant differences; the same experiments performed with 8 keV ions at a scattering angle of 2° indicate a clear difference in the absolute abundances of the two main daughter ions. High-energy collisions of MH+ ions obtained by fast atom bombardment lead to different spectra at both 0° and 2° scattering angles, proving that the energy deposition in the preselected species is an important parameter. Low-energy collisions with argon of MH+ ions generated by positive-ion chemical ionization (NH4+) give rise to almost identical energy-resolved mass spectra, whereas the same experiments using helium as target gas lead to a clear distinction between the two isomers.

Fast atom bombardment and angle resolved mass spectrometry in the structural and stereochemical characterization of homochiral 3-deoxy-3-fluoro muscarins

The mass spectrometric behaviour of four homochiral 3-deoxy-3-fluoro muscarins has been studied by means of fast atom bombardment. Neither naturally occurring nor collisionally induced decompositions were effective for the structural characterization of the different diastereoisomers. In contrast such results have been easily obtained by angle-resolved mass spectrometry, i.e. by the study of the variation of absolute abundance of collisionally induced decomposition products versus scattering angle.

Scatter profiling and the extent of product ion angular scattering in some non-dissociative polyatomic collisions of kiloelectronvolt energy ions with stationary target-gas particles

Relative angular-differential cross-sections for selected physical reactions occurring during collisions of kiloelectronvolt-ions with target-gas particles, were obtained using the technique of “scatter profiling” in which the scatter cone of product ions is sampled at various heights above the plane containing the incident ion beam. Although such data need to be numerically transformed to extract the angular dependence, the less-stringent need for beam collimation (compared with angle-resolved mass spectrometry) means that the technique can be performed on unmodified commercial ZAB-series instruments and can give higher signal-to-noise ratios. After consideration of some ionized-Ar-Ar reactions to establish the technique, two types of process were studied. Double-electron-capture (charge-inversion) reactions of 4 keV OH + or F + ions with Xe, CS 2 or OCS target molecules were studied to illustrate the variation of the “most probable” laboratory-frame scatter angle with curve-crossing radius. For OH − product ions, the observed values were small (< 0.2°) and were in approximate agreement with the calculated values, but for F − ions, scattering was larger than expected, suggesting that the curve crossings, at comparatively large distances (> 3.3 Å), are outside the respective reaction windows. Charge stripping and other excitation reactions of 4 keV, CS + 2, CO + 2, N + 2 and NO + with He and Ar target atoms were then studied, the extent of scatter being found to be relatively large and dependent upon both the reaction endothermicity and upon target-gas type.

Tandem‐Massenspektrometrie — Grundlagen und Applikationen

AbstractThe fragmentation of metastable and collisionally activated ions as well as different experimental techniques which can be used to record daughter, parent and neutral loss spectra are discussed in the first part of this review. Advanced MS/MS methods are represented by the Neutralization Reionisation Mass Spectrometry (NRMS) which allows the characterization of neutral species and the angular resolution of the ion beam emerging from a collision cell, lending to Angle Resolved Mass Spectrometry (ARMS).Typical applications of the tandem mass spectrometry are given by the determination of ion structures, the gas phase reactions of ions and the analysis of compounds in complex mixtures.

Experimental and theoretical investigations of angular distributions of fragments from dissociations of polyatomic ions

The possibility of correcting relative intensities of fragment ions obtained by angle-resolved mass spectrometry, for the effects of translational energy release, was investigated. The computational procedure is essentially an extension of that described by Todd et al. [10] to take account of a distribution function for translational energy release. The theoretical model permits derivation of a condition under which the deconvolution should be least ambiguous. In practice, the limiting features of the procedure appear to be lack of knowledge of the translational energy release distributions, and the very poor inter-laboratory reproducibility of the experimental data. Some experimental data are reported here for the case of the molecular ions of n-butylbenzene, obtained under conditions of high angular resolution (±0.02°). Floating the collision cell electrically, to separate unimolecular and collision-induced reactions, is shown to have a marked effect upon both relative intensities and values of translational energy release. Reasonable agreement was obtained between the present experimental data and theoretical predictions.

A comparison of charge-exchange, energy-resolved and angle-resolved mass spectrometric methods for studying the energy dependence of ionic fragmentation reactions

The energy dependence of the fragmentation of the molecular ions of benzyl methyl ether, nitrobenzene, cyclohexene, n-propanol and nitromethane have been studied by charge-ex-change mass spectrometry (CEMS) and energy-resolved mass spectrometry (ERMS) (low, variable energy collision-induced mass spectrometry). The majority of these systems had previously been studied by angle-resolved mass spectrometry (ARMS). A comparison of the results obtained by CEMS and ARMS shows that the variations of fragment ion yields with scattering angle in ARMS are consistent with an increase in the translational energy converted to internal energy with an increase in the angle of observation. The comparison of the CEMS and ERMS results shows that the translational energy transformed into internal energy in ERMS increases initially with increasing ion kinetic energy but, in many cases, reaches a maximum. Hence, the technique is only suitable for studying the low energy fragmentation reactions of gaseous ions. Contrasting results are obtained by CEMS and ERMS for the nitromethane system and it is proposed, by comparison with photoelectron/photoion coincidence data, that the collision processes produce ions with relatively high internal energies which show a different fragmentation behaviour than the low energy ions produced by charge exchange. The same explanation may apply for the ARMS data, where it has been proposed that the apparently anomalous results are interpretable in terms of angular distribution of products due to kinetic energy release effects in the fragmentation processes.

The variation of translational energy release in collision-induced dissociations of polyatomic ions with initial kinetic energy and with observation angle. I. Theoretical considerations

Angle-resolved mass spectrometry has hitherto focused upon variations in relative yields of fragment ions formed in collision-induced dissociations. This paper investigates the sequence of assumptions which must be made in order to interpret observed variations in peak widths, as the observation angle is varied, in terms of energy deposited in the projectile ion by the collision. Some of these assumptions, such as the nature of the collisional excitation mechanism, and the relationship of the energy thus deposited to the total internal energy of those ions sampled by the fragmentation process, are common to both types of experiment. Other assumptions, such as the manner in which the total internal energy of the reacting ion is partitioned into translational energy of the fragments, are peculiar to the peak width measurements. The latter, however, are free from ambiguities of interpretation arising from convolution of the collisional scattering with differences in angular distributions of fragment ions arising only from differences in translational energy release. For both types of experiment the situation is complex, and interpretation requires considerable care.

An energy-resolved study of the fragmentation of ionized 3-penten-2-ol. A comparison of charge exchange, field ionization kinetics and angle-resolved mass spectrometry

The dependence of the fragmentation of the 3-penten-2-ol-1,1,1- d 3 molecular ion on internal energy has been investigated by charge exchange mass spectrometry over the internal energy range from metastable ions to ∼ 6.3 eV. At low internal energies, fragmentation by loss of CH 3 is favoured, but loss of CD 3 increases rapidly in importance with increasing internal energy until ∼6 eV internal where CH 3 and CD 3 are lost with about equal probability. The results are compared with earlier field ionization kinetics (FIK) and angle resolved mass spectrometry (ARMS) results. This comparison shows that the FIK results in the time range 10 −9 to 10 −11 s refer to ions with internal energies in the 1–4 eV range, while the ARMS results are best interpreted in terms of variation of the energy deposition function with angle of observation of the fragmentation products.

Angle-dependence of ion kinetic energy spectra obtained by using mass spectrometers I. Theoretical consequences of conservation laws for collisions

Collision-induced processes for ion beams in the kilovolt energy range have been studied in mass spectrometers since the inception of the technique (‘Aston bands’). In most such studies to date, the fast collision products bave been collected over a range of angles relative to the initial projectile trajectory, this range being defined by the ion optics of the instrument used. More recently, there has been some interest in controlling and exploiting the collection angle for the fast collision products. The motivation behind such studies may be expressed qualitatively in terms of the more violent collisions favouring higher-energy processes, and also resulting in a larger scattering angle for the projectile ion in the activating collision. Thus, it might be hoped that collection angle could serve as an experimental parameter whose variation controls the energetics of the collision-induced processes actually observed. The present work examines the probable limitations of such an approach, on the basis of classical collision theory. Even without knowledge of an appropriate potential function for the projectile ion-neutral target interaction, it is possible to obtain useful quantitative information concerning such collisions. The extensive work on monatomic projectiles and targets is reviewed, and an attempt made to extend these results to polyatomic species of more interest to the mass spectrometrist. When the collision induced process to be studied is chemical fragmentation, the observed angular distribution is a convolution of two effects of comparable importance, namely the scattering angle-energy deposition relation which is the desired result of the experiment, and the internal energy of the projectile (precursor) ion released as excess translational energy of the fragments. The most recent experimental work on angle-resolved mass spectrometry is critically discussed in the light of these considerations.

Improved performance in angle-resolved mass spectrometry

A new experimental arrangement for angle-resolved mass spectrometry is described featuring a needle which delivers collision gas to the source slit of a reversed geometry mass spectrometer. In this experiment the scattering angle is defined by pre-collision electrical deflection of the parent ion beam, as contrasted with post-collision selection of the direction of the daughter ion beam. Advantages are rapid access to any desired angle, coupled with an improvement in ion intensity and in angular resolution evident from measured breakdown curves. Collision-induced dissociation spectra of the methanol molecular ion, recorded over a range of scattering angles, agree well with previous results. Experiments which record ions that survive collisions, i.e., scatter without fragmentation, indicate that scattering of polyatomic ions through substantial angles (0–6°) makes a significant contribution to the phenomena underlying angle-resolved mass spectrometry.

Angle-resolved mass spectrometry

Scattering of ions in the z-direction during inelastic collisions with gas molecules has been used to study the energetics of various ion reactions. Charge-stripping spectra and mass-analysed ion kinetic energy spectra are illustrated as a function of angle. The theoretical basis of inelastic scattering is critically assessed and the importance of pre- and post-collimation of the ion beam stressed.

Energy-resolved collision-induced dissociation in tandem mass spectrometry

The effects of ion kinetic energy upon the low-energy collision-induced dissociation (CID) process in triple quadrupole mass spectrometry (MS/MS) are investigated. Energy-resolved CID breakdown curves are compared to those from quasi-equilibrium theory (QET) and angle-resolved mass spectrometry. The use of breakdown curves for the differentiation of isomeric ion structures is also investigated In addition. associative collisions with reactive collision gases are studied by energy-resolved MS/MS. These techniques provide a better understanding of the low-energy collision process in MS/MS and are essential in determining standard conditions for recording MS/MS library spectra

Angle-resolved mass spectrometry by ‘z-deflected’ scanning

Angle-resolved mass spectrometry by ‘z-deflected’ scanning

Angle-resolved mass spectrometry. Target effects upon energy deposition

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAngle-resolved mass spectrometry. Target effects upon energy depositionP. H. Hemberger, J. A. Laramee, A. R. Hubik, and R. G. CooksCite this: J. Phys. Chem. 1981, 85, 16, 2335–2340Publication Date (Print):August 1, 1981Publication History Published online1 May 2002Published inissue 1 August 1981https://doi.org/10.1021/j150616a008RIGHTS & PERMISSIONSArticle Views49Altmetric-Citations32LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (694 KB) Get e-Alerts

Kinetic energy effects in mass spectrometry/mass spectrometry using a sector/quadrupole tandem instrument

Using a new hybrid (magnet/quadrupole) tandem mass spectrometer the effects of ion kinetic energy and target mass upon energy deposition have been investigated. In the range 1–100 eV, the degree of fragmentation is very sensitive to changes in the translational energy of the parent ion. Comparisons with MS/MS spectra recorded for the same ions (protonated 5-indanol, protonated diethylamine) using other instruments show that less significant changes in spectra occur in the kV energy range. Plots of branching ratios for competitive collision-induced dissociation channels against collision energy (1–100 eV) resemble, qualitatively, breakdown curves displaying ion abundances versus internal energy. In addition, comparisons of the effect of collision energy are made with spectral changes resulting from selection of the scattering angle in kV energy collisions. It is evident that translational energy selection is a counterpart, for spectrometers operating at low translational energy, of angle-resolved mass spectrometry.

Dissociative excitation of gas-phase ions. A comparison of techniques utilizing ion cyclotron resonance spectroscopy and angle-resolved mass spectrometry

A comparison is made between electron-impact dissociation of ions in an ion cyclotron resonance (ICR) spectrometer and collision-induced dissociation performed in a mass spectrometer capable of selecting scattering-angles. These experiments both probe ion structure by monitoring unimolecular dissociation following excitation. The techniques have been applied to the molecular ions of trifluorotoluene, phenetole, aniline, n-propyl-benzene, and perfluoropropylene. Plots of relative fragment-ion abundance versus electron energy (in the range 2–9 eV) are compared to similar plots in which the abscissa is the scattering angle (known to be related in some systems to internal energy). The plots are found to be qualitatively similar for the two techniques for several of the molecular ions, but significantly different for two. For one of these, perfluoropropylene, a lack of dependence of fragment-ion abundance upon scattering angle was observed, implying that the ion internal energy does not vary with scattering angle. The differences between the electron- and particle-impact behavior may stem from the fact that fluorescence or rotational excitation are implicated. Although both methods suffer from some uncertainty in defining precisely the internal energy deposition they are simple to effect yet yield important fundamental information about ion dissociation chemistry.

ChemInform Abstract: UNIMOLECULAR DISSOCIATIONS AT SHORT TIMES. A COMPARISON OF ANGLE‐RESOLVED MASS SPECTROMETRY AND FIELD IONIZATION KINETICS

Chemischer InformationsdienstVolume 12, Issue 17 Physical Organic Chemistry ChemInform Abstract: UNIMOLECULAR DISSOCIATIONS AT SHORT TIMES. A COMPARISON OF ANGLE-RESOLVED MASS SPECTROMETRY AND FIELD IONIZATION KINETICS D. J. BURINSKY, D. J. BURINSKYSearch for more papers by this authorG. L. GLISH, G. L. GLISHSearch for more papers by this authorR. G. COOKS, R. G. COOKSSearch for more papers by this authorJ. J. ZWINSELMAN, J. J. ZWINSELMANSearch for more papers by this authorN. M. M. NIBBERING, N. M. M. NIBBERINGSearch for more papers by this author D. J. BURINSKY, D. J. BURINSKYSearch for more papers by this authorG. L. GLISH, G. L. GLISHSearch for more papers by this authorR. G. COOKS, R. G. COOKSSearch for more papers by this authorJ. J. ZWINSELMAN, J. J. ZWINSELMANSearch for more papers by this authorN. M. M. NIBBERING, N. M. M. NIBBERINGSearch for more papers by this author First published: April 28, 1981 https://doi.org/10.1002/chin.198117061AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume12, Issue17April 28, 1981 RelatedInformation