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International Journal of Mass Spectrometry and Ion Physics最新文献

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Fragmentation probability in collisional-activation mass spectrometry (Ca/MS). II. Effect of daughter-ion cross-section 碰撞活化质谱(Ca/MS)中的碎片概率。2离子截面的影响
International Journal of Mass Spectrometry and Ion Physics Pub Date : 1983-07-01 DOI: 10.1016/0020-7381(83)85013-X
Myung S. Kim
{"title":"Fragmentation probability in collisional-activation mass spectrometry (Ca/MS). II. Effect of daughter-ion cross-section","authors":"Myung S. Kim","doi":"10.1016/0020-7381(83)85013-X","DOIUrl":"10.1016/0020-7381(83)85013-X","url":null,"abstract":"<div><p>Probability theory is used to describe the effect of the cross-sections for collisional ion-loss of daughter ions on fragmentation yield in collisional-activation mass spectrometry (CA/MS). Expressions for the parent-ion and total daughter-ion intensities are derived using the usual two-step model for the collisional-activation (CA) process and also for the more general sequential excitation model proposed previously. A smaller cross-section for the loss of daughter ions by collision as compared to that of the parent is found to affect the experimental CA data (daughter vs. parent intensities) in a similar way to sequential excitation. Independent determination of relative ion-loss cross-sections for daughter ions seems to be needed to obtain information concerning the dynamics and energetics of a CA process from CA experiments.</p></div>","PeriodicalId":13998,"journal":{"name":"International Journal of Mass Spectrometry and Ion Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7381(83)85013-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90759354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 12
Ion sources for mass spectrometry. II. Filaments for low temperature ion sources 质谱分析用离子源。2用于低温离子源的灯丝
International Journal of Mass Spectrometry and Ion Physics Pub Date : 1983-07-01 DOI: 10.1016/0020-7381(83)85007-4
L. Kelner, S.P. Markey, H.M. Fales, P.A. Cole , C.K. Crawford
{"title":"Ion sources for mass spectrometry. II. Filaments for low temperature ion sources","authors":"L. Kelner,&nbsp;S.P. Markey,&nbsp;H.M. Fales,&nbsp;P.A. Cole ,&nbsp;C.K. Crawford","doi":"10.1016/0020-7381(83)85007-4","DOIUrl":"https://doi.org/10.1016/0020-7381(83)85007-4","url":null,"abstract":"<div><p>Two low power filaments (thin wire rhenium-and LaB<sub>6</sub>) have been designed to allow a chemical-ionization ion source to operate below 100°C. Both filaments simplified analysis of the thermally sensitive compound flurazepam using negative chemical-ionization mass spectrometry. The Lab<sub>6</sub> cathode is susceptible to poisoning from solvents with temporary loss of thermionic emission. This effect has been studied using various organic solvents.</p></div>","PeriodicalId":13998,"journal":{"name":"International Journal of Mass Spectrometry and Ion Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7381(83)85007-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136940971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Crossedelectric-magnetic field electron-capture ion source 交叉电磁场电子俘获离子源
International Journal of Mass Spectrometry and Ion Physics Pub Date : 1983-07-01 DOI: 10.1016/0020-7381(83)85005-0
J.E. Delmore
{"title":"Crossedelectric-magnetic field electron-capture ion source","authors":"J.E. Delmore","doi":"10.1016/0020-7381(83)85005-0","DOIUrl":"10.1016/0020-7381(83)85005-0","url":null,"abstract":"<div><p>A method for thermalizing electrons is presented which involves the acceleration of electrons away from a hot filament with crossed electric-magnetic (EXB) fields in a magnetron configuration. It is shown that during a part of the resulting cycloidal path the electron velocity is significantly less than the initial velocity. The electron accelerates as it leaves the surface at a rate only slightly less than if there were no magnetic field, which prevents charge build-up at the surface. As the electron traverses the cycloid it is decelerated during the 2nd, 3rd and 4th quadrants, then re-accelerated as it approaches the end of the 4th quadrant to regain its original velocity. The minimum velocity occurs during the 4th quadrant, and corresponds to an electron temperature of 200–500°C for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source modeled from this principle is presented.</p></div>","PeriodicalId":13998,"journal":{"name":"International Journal of Mass Spectrometry and Ion Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7381(83)85005-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82784164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 13
Effect of energetic electrons on breakdown graphs determined by threshold photoelectron-photoion coincidence (TPEPICO) mass spectrometry using steradiancy analyzers 高能电子对使用稳态分析仪的阈值光电子-光离子重合质谱测定的击穿图的影响
International Journal of Mass Spectrometry and Ion Physics Pub Date : 1983-07-01 DOI: 10.1016/0020-7381(83)85015-3
Jerome P. Gilman, Tacheng Hsieh , G.G. Meisels
{"title":"Effect of energetic electrons on breakdown graphs determined by threshold photoelectron-photoion coincidence (TPEPICO) mass spectrometry using steradiancy analyzers","authors":"Jerome P. Gilman,&nbsp;Tacheng Hsieh ,&nbsp;G.G. Meisels","doi":"10.1016/0020-7381(83)85015-3","DOIUrl":"10.1016/0020-7381(83)85015-3","url":null,"abstract":"<div><p>In TPEPICO mass spectrometry, a threshold photoelectron detector is employed to transmit zero kinetic energy electrons. The steradiancy analyzer normally employed allows a small but significant number of non-zero kinetic energy electrons to be transmitted as well. A method has been developed to estimate the contribution to measured breakdown graphs of energetic electrons transmitted through the detector. This technique consists of convoluting the known instrument function and the HeI photoelectron spectrum (PES) with various postulated breakdown curves until the experimental and calculated breakdown curves match. This method has been successfully applied to propane and the C<sub>4</sub>H<sub>8</sub> isomers, but it cannot be applied when the HeI PES does not represent the internal energy distribution in the energy range being examined. This is the case for CF<sub>3</sub>I; for such cases it is possible to construct a variable-energy PES if the HeI PES, the real breakdown graph and the instrument function are known.</p></div>","PeriodicalId":13998,"journal":{"name":"International Journal of Mass Spectrometry and Ion Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7381(83)85015-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88115754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 10
Secondary-ion mass spectrometry (SIMS) of organic compounds. II. Mass spectra of peptides 有机化合物的二次离子质谱分析。2多肽质谱
International Journal of Mass Spectrometry and Ion Physics Pub Date : 1983-07-01 DOI: 10.1016/0020-7381(83)85009-8
K. Weyer, K.D. Klöppel, G. Von Bünau
{"title":"Secondary-ion mass spectrometry (SIMS) of organic compounds. II. Mass spectra of peptides","authors":"K. Weyer,&nbsp;K.D. Klöppel,&nbsp;G. Von Bünau","doi":"10.1016/0020-7381(83)85009-8","DOIUrl":"10.1016/0020-7381(83)85009-8","url":null,"abstract":"<div><p>Secondary-ion mass spectra of the dipeptides Gly-Gly, Gly-Leu, Phe-Gly, Meth-Phe, the tripeptides Gly-Gly-Gly, Leu-Leu-Leu, Gly-Leu-Ala, Gly-Pro-Ala, the tetrapeptides Phe-Gly-Phe-Gly, Pro-Phe-Gly-Lys, and the octapeptide Asp-Arg-Val-Tyr-Ile-His-Pro-Phe (angiotensin II) were recorded using bare silver targets and targets covered with mixtures of the peptides and glycerol. Spectra were compared with those obtained by chemical ionization (CI) with isobutane as a reactant gas, electron impact ionization (EI), and field desorption (FD). Secondary ionization (SI) was established to be less destructive than EI and CI and to yield more characteristic fragment ions than FD without loss of information on the molecular mass <em>M</em>; e.g. the abundance of the protonated angiotensin II molecule MH<sup>+</sup> (1046 mass units) was measured to be 9.2% of that of the base peak. SI leads mainly to fragmentation of the peptide bonds. This permits application of SIMS to sequence analysis of minute quantities of oligopeptides.</p></div>","PeriodicalId":13998,"journal":{"name":"International Journal of Mass Spectrometry and Ion Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7381(83)85009-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86343010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Field-ionization kinetic measurements using wire emitters 使用线发射体的场电离动力学测量
International Journal of Mass Spectrometry and Ion Physics Pub Date : 1983-07-01 DOI: 10.1016/0020-7381(83)85017-7
K. Levsen, E. Hilt, I. Goldenfeld
{"title":"Field-ionization kinetic measurements using wire emitters","authors":"K. Levsen,&nbsp;E. Hilt,&nbsp;I. Goldenfeld","doi":"10.1016/0020-7381(83)85017-7","DOIUrl":"10.1016/0020-7381(83)85017-7","url":null,"abstract":"","PeriodicalId":13998,"journal":{"name":"International Journal of Mass Spectrometry and Ion Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7381(83)85017-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83948664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Influence of ion energy distributions and matrix effects on spark source mass spectrometric analysis 离子能量分布和基质效应对火花源质谱分析的影响
International Journal of Mass Spectrometry and Ion Physics Pub Date : 1983-06-01 DOI: 10.1016/0020-7381(83)85029-3
L. Vos, R. Van Grieken
{"title":"Influence of ion energy distributions and matrix effects on spark source mass spectrometric analysis","authors":"L. Vos,&nbsp;R. Van Grieken","doi":"10.1016/0020-7381(83)85029-3","DOIUrl":"10.1016/0020-7381(83)85029-3","url":null,"abstract":"<div><p>The energy distributions of ions produced in a spark source mass spectrometer were recorded for different trace element ions and for the total ion current. Both electrodes of pure doped graphite, and with 10% potassium salts added, were examined. The results show that the measured energy of an ion is mainly determined by the <em>m/z</em> ratio and that the energy of the total ion current depends on the sample composition. It was also clear that if the accelerating voltage is set to obtain maximum transmission of the total ion current, the fraction of the heavy elements that is discriminated at the β-slit depends on the matrix composition if the pass band of the instrument is narrow. These effects influence considerably the accuracy in the analysis of variable samples.</p></div>","PeriodicalId":13998,"journal":{"name":"International Journal of Mass Spectrometry and Ion Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7381(83)85029-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84188719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 8
Time-resolved measurements in spark source mass spectrometry. I. Deflection of the ion beam 火花源质谱法的时间分辨测量。1、离子束偏转
International Journal of Mass Spectrometry and Ion Physics Pub Date : 1983-06-01 DOI: 10.1016/0020-7381(83)85030-X
M. Viczián, I. Cornides, J. Van Puymbroeck, R. Gijbels
{"title":"Time-resolved measurements in spark source mass spectrometry. I. Deflection of the ion beam","authors":"M. Viczián,&nbsp;I. Cornides,&nbsp;J. Van Puymbroeck,&nbsp;R. Gijbels","doi":"10.1016/0020-7381(83)85030-X","DOIUrl":"10.1016/0020-7381(83)85030-X","url":null,"abstract":"<div><p>The synchronous passer system of a JEOL spark source mass spectrometer was modified so that the ion beam could be deflected at a variable time after the start of the first of a series of discharges. The transmitted part of the ion beam was analyzed by photoplate detection.</p><p>Time-resolved measurements revealed a different behaviour between different ionic species of the same <em>m/z</em> value. The singly-charged atomic ions were delayed by (150±100) ns with respect to the multiply-charged ions. Molecular ions were found to be delayed by about 700 ns (C<sub><em>n</em></sub><sup>+</sup>) or even one or more μs (S<sub><em>n</em></sub><sup>+</sup>, SC<sub><em>n</em></sub><sup>+</sup>) relative to multiply-charged ions.</p><p>The duration of the production/extraction process of multiply- and singly-charged ions was well defined in time, while this process could last for several μs in the case of polyatomic ions.</p></div>","PeriodicalId":13998,"journal":{"name":"International Journal of Mass Spectrometry and Ion Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7381(83)85030-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87644962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 10
On the structure of CH3O2+ CH3O2+的结构
International Journal of Mass Spectrometry and Ion Physics Pub Date : 1983-06-01 DOI: 10.1016/0020-7381(83)85025-6
H. Villinger, R. Richter, W. Lindinger
{"title":"On the structure of CH3O2+","authors":"H. Villinger,&nbsp;R. Richter,&nbsp;W. Lindinger","doi":"10.1016/0020-7381(83)85025-6","DOIUrl":"10.1016/0020-7381(83)85025-6","url":null,"abstract":"<div><p>Protonated formic acid and CH<sub>3</sub>O<sub>2</sub><sup>+</sup> produced in the reaction of O<sub>2</sub><sup>+</sup> with CH<sub>4</sub> both undergo the same isotopic exchange reactions with D<sub>2</sub>O and show the same dissociation pattern, indicating that both have the structure <figure><img></figure>.</p></div>","PeriodicalId":13998,"journal":{"name":"International Journal of Mass Spectrometry and Ion Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7381(83)85025-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78271770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 26
Secondary-ion mass spectrometry (SIMS) of organic compounds. I. Sample preparation methods 有机化合物的二次离子质谱分析。一、样品制备方法
International Journal of Mass Spectrometry and Ion Physics Pub Date : 1983-06-01 DOI: 10.1016/0020-7381(83)85028-1
K.D. Klöppel, K. Weyer, G. Von Bünau
{"title":"Secondary-ion mass spectrometry (SIMS) of organic compounds. I. Sample preparation methods","authors":"K.D. Klöppel,&nbsp;K. Weyer,&nbsp;G. Von Bünau","doi":"10.1016/0020-7381(83)85028-1","DOIUrl":"10.1016/0020-7381(83)85028-1","url":null,"abstract":"<div><p>Highly porous targets for SIMS were prepared by thermal decomposition of metal compounds on foils of the respective metals. Compounds and foils of silver, gold and tantalum were compared with respect to secondary-ion (SI) intensities measured after spreading solutions of a test substance, phenylalanine hydrochloride, on the porous metal surface. Highest SI intensities were found with silver surfaces obtained after thermal decomposition of silver carbonate. SI intensities depend on primary-(argon) ion flux, on the concentration of the spread solution, and on additives, such as proton donators. It was found that porous targets perform much better than smooth ones with respect to avoiding rapid depletion of substances from the area of the target hit by the primary ions. Further improvement was achieved in some cases by covering the target with a mixture of the sample and some involatile solvent, such as glycerol.</p></div>","PeriodicalId":13998,"journal":{"name":"International Journal of Mass Spectrometry and Ion Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7381(83)85028-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85217452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 6
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