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1.
L. M. Lopez Marin D. Promé M. A. Lanéelle M. Daffé J. C. Promé 《Journal of the American Society for Mass Spectrometry》1992,3(6):656-661
Mycobacteria contain species- and type-specific antigens. Among them, glycopeptidolipids are present in medically relevant organisms belonging to Mycobacterium avium or M. fortuitum complexes. Fast-a tom bombardment mass spectrometry of glycopeptidolipids has proven to be difficult. In this article the cationization method with a metanitrobenzyl alcohol matrix, doped with sodium iodide, is described for analyzing these molecules. The molecular weight of the intact glycopeptidolipids was successfully determined and, using mass-analyzed ion kinetic energy spectrometry, the complete sequences of the peptide and saccharide moieties were elucidated. Moreover, the two structural variants present in these molecules were clearly differentiated. Application of the method showed that the same structural variant occurs in the glycopeptidolipids from two serologically related species of the M. fortuitum complex. 相似文献
2.
Fast atom bombardment mass spectra of a series of naturally occurring and synthetically modified iridoid glycosides were studied using lithium cationization and collision-induced dissociation of the resulting [M+Li]+ ions. Lithium cationization leads to the unambiguous determination of the molecular masses of these compounds. Collision-induced dissociation of the lithiated molecular ions give valuable structural information regarding the nature of the substituent on both the aglycone and the sugar moieties. The characteristic fragmentation pathways identified are (1) elimination of neutral molecules comprising the substituents on either the aglycone or sugar moieties, (2) formation of lithiated aglycone and their fragment ions, (3) formation of lithiated sugar and their fragment ions, (4) fragmentation corresponding to the cleavage of the aglycone or sugar ring and (5) fragmentation characteristic of the substituents present in either the aglycone or sugar parts of the molecule. Elimination of two acyloxy radicals from the lithiated molecular ion is a characteristic fragmentation in the case of acyloxy derivatives. 相似文献
3.
Three saponins were extracted and isolated from starfish by reversed-phase high performance liquid chromatography (HPLC), and analyzed by fast atom bombardment mass spectrometry (FAB-MS). Their molecular weight information could be obtained by the presence of abundant [M+Na]+ ions and weak [M+H]+ ions in FAB-MS spectra. Moreover, high resolution mass measurements of their [M+Na]+ ions were performed at the resolution of 10000 to elucidate the element composition of extracted saponins. The collision-induced dissociation (CID) of sodium-adducted molecules [M+Na]+ yielded diverse product ions via dissociated processes. In the collision-induced dissociation (CID)-MS/MS analysis of [M+Na]+ ion, the sulfate-containing saponins produced characteristic ions such as SO4Na+, [NaHSO4+Na]+, [M+Na-sugar]+ and [M+Na-2sugar]+ ions, whereas the sulfate-free compound showed characteristic ions produced by cleavage of sugar moiety and side chain of aglycone. The fragmentation patterns could provide information on the linkage position of sugar groups in aglycone and sulfate groups. 相似文献
4.
D. D. Fetterolf B. L. Lawson D. J. Hoch T. C. Pinkerton 《Journal of Radioanalytical and Nuclear Chemistry》1985,94(1):63-70
Negative Ion Fast Atom Bombardment Mass Spectrometry is conducted on potassium pertechnetate evaporated onto a copper probe. The mass spectra of pertechnetate /TcO
4
–
/ reveal the presence of mononuclear and polynuclear technetium oxo species which form general series TcnO
n+1
–
,...TcnOn+4 with n=1 to 5. The polynuclear species are believed to be formed via gas phase reactions. 相似文献
5.
《International journal of mass spectrometry and ion processes》1984,55(3):221-232
Fast atom bombardment mass spectrometry (FAB-MS) has rapidly become established, after its introduction two years ago, as a method of choice for mass spectral analysis of higher molecular weight polar organic chemicals. In industrial analysis, the technique has been found to be a very effective method for analyzing numerous classes of polar polymeric chemicals, including rubber and plastic additives, organometallics, and polar polymers. Normally applied in conjunction with field desorption (FD-MS), FAB-MS is used to determine chemical structures for both pure compounds and oligomeric mixtures. Fast atom bombardment results for poly(ethylene glycol) and poly(propylene glycol) show that, while oligomer quasimolecular ion distributions give a rough indication of relative oligomer abundances, the data are not quantitative in comparison with that previously described for FD-MS (or electrohydrodynamic ionization, EH-MS) analysis. More specifically, lower mass oligomer intensities tend to be too high in FAB-MS due to fragmentation reactions. 相似文献
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Denekamp C Van Den Heuvel H Voinov VG Claeys M Seto C Grossert JS Waddell DS Curtis JM Boyd RK 《Rapid communications in mass spectrometry : RCM》2000,14(12):1035-1043
In this study we report on high-energy, collision-induced dissociation processes leading to charge-remote fragmentations, using three alkyl cations, namely n-hexadecylpyridinium, n-hexadecyltriphenylphosphonium and n-hexadecyltriethylammonium, each with and without (2)H(2)-labelling at the C(9) position of the hexadecyl chain. The characteristic patterns corresponding to the formal elimination of alkane elements were observed, and the (2)H(2)-labelling at C(9) clearly affected only one charge-remote fragment ion of the homologous series. However, in addition to the expected fragment ion containing only one deuterium atom, a significant ion retaining two deuterium atoms was observed. MS/MS/MS experiments demonstrated clearly that the latter ion showed partial deuteration around the charge site, the level of deuteration depending on the structure of the original precursor cation. These results can be interpreted in terms of two novel, distinct mechanisms, one of which involves an excited state in an aromatic ring. Mixed-site fragmentation (MSF) ions were also observed from the phosphonium and ammonium ion precursors. We believe that the observation of the MSF process occurring at an sp(2)-hybridized center in the phosphonium series has not been reported previously. It thus becomes apparent that high-energy collisions leading to charge-remote reactions in fact lead to a broad range of pathways. Copyright 2000 John Wiley & Sons, Ltd. 相似文献
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9.
The positive and negative fast atom bombrdment spectra of two groups of simple salts have been recorded. The structures of the major ionic species of eight chlorides and five, complex anion, sodium salts have been interpreted and tabulated. 相似文献
10.
The review article is devoted to the mass spectrometry method of ionization of material by fast atom bombardment (FAB). The FAB method extends the possibilities of mass spectrometry by making it possible to obtain the mass spectra of nonvolatile, thermally unstable, and high-polarity compounds, which contain information on the molecular weight and the structure of the compounds studied. The mechanism of ion formation, the apparatus design, and also the main results of FAB mass spectrometric study of different classes of compounds are examined. This method is specially helpful in analysis of natural compounds.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 23, No. 1, pp. 62–78, January, 1987. 相似文献
11.
Gustav Bojesen 《Journal of mass spectrometry : JMS》1985,20(6):413-415
It is shown that fast atom bombardment mass spectrometry is well suited for the study of coordination compounds. 相似文献
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14.
Gui-Xiang Fu Zhang-Lin Zhou Lu Yu Yao-Zeng Huang 《Journal of mass spectrometry : JMS》1992,27(6):695-698
The fast atom bombardment (FAB) mass spectra of telluronium salts were studied. The spectra exhibit the intact cation (C+) and cluster ions ([M + C]+). The principal fragment ions in the FAB mass spectra of telluronium salts are [RTe]+, [R2Te]+˙, [R2Te − H]+, [RTeR′]+˙, and [RTeR′ + H]+. When the anion was [BPh4]−, interesting cluster ions such as [M + C − BPh3]+ appeared. 相似文献
15.
Positive-ion fast atom bombardment mass spectra and linked-scan tandem mass spectra were measured for aromatic iodonium salts. The mass spectra usually contain the intact cation of the iodonium salt as the base peak, fragment ions of lower abundance resulting from simple cleavages or rearrangements, and a characteristic loss of atomic iodine. High-level semi-empirical calculations suggest that an obtuse ring? I+? ring angle facilitates loss of atomic iodine through concomitant ring? to? ring bond formation. 相似文献
16.
Russell P. Newton Andrea M. Evans Hamed G. Hassan Terence J. Walton A. Gareth Brenton Frank M. Harris 《Journal of mass spectrometry : JMS》1993,28(8):899-906
The syntheses of 2′-O-succinyl, 2′-O-succinyltyrosinyl methyl ester and 2′-O-succinyliodotyrosinyl methyl ester derivatives of a cyclic nucleotide, derivatives necessary for the successful development of a specific radioimmuno-assay, are described. Fast atom bombardment with collision-induced dissociation and mass-analysed ion kinetic energy spectroscopy were used to verify the positions of substitution and the retention of the 3′,5′-cyclic phosphate moiety. Comparison of spectra produced after different iodination times permitted the optimization of the reaction conditions. 相似文献
17.
Lin Yan Wengang Chai Guanghui Wang Guanli Wu Kaijuan Lu Yue Luo 《Journal of mass spectrometry : JMS》1987,22(5):279-282
During a comparison study of the fast atom bombardment (FAB) and electron impact mass spectra of 1-organyl-2,9,10-trioxa-6-aza-1-silatricyclo[4.3.3.01,6]dodecanes, an unusual ion peak at m/z 164 was noticed in the FAB spectra. Accurate mass measurement indicated that m/z 164 corresponds to protonated 1-[N,N-bis(2-hydroxyethyl)amino]-1-propanol (BHAP), which is produced by a ring-rupture reaction. Further experiment showed that the intensity of the [BHAP + H]+ ion peak increased markedly as the 7keV Ar0 bombardment proceeded, suggesting a FAB-induced reaction. The possible mechanism is also discussed. 相似文献
18.
Chris G. de Koster Gerard J. Niemann Wigger Heerma 《Fresenius' Journal of Analytical Chemistry》1986,323(4):321-325
Summary Ten hydroxybenzoic acids were analysed by positive and negative-ion fast atom bombardment mass spectrometry. FAB-MS of all acids investigated gave intense (M+H)+ or (M-H)– ion peaks. Isomers could be distinguished by the metastabile ion or collisional activation spectra of selected ions, except for m- and p-hydroxybenzoic acid. These compounds could be distinguished, however, by the charge stripping spectra of the (M-H)– ions.
FAB-Massenspektrometrie von Hydroxybenzoesäuren
Zusanunenfassung Zehn Hydroxybenzoesäuren wurden mit Hilfe der FAB-Massenspektrometrie (positive und negative Ionen) analysiert. Alle untersuchten Säuren ergaben intensive (M+H)+-oder (M–H)–-Ionenpeaks. Isomere konnten mit Hilfe der Spektren metastabiler Ionen oder von Kollisions-Aktivierungsspektren ausgewahlter Ionen unterschieden werden, außer m- und p-Hydroxybenzoesäure, die durch Charge-stripping-Spektren der (M-H)–-Ionen unterschieden wurden.相似文献
19.
Hiroko F Kasai Masayoshi Tsubuki Kazunori Takahashi Toshio Honda Haruhisa Ueda 《Analytical sciences》2003,19(12):1593-1598
The utility of the collision-induced dissociation (CID) of two different forms of precursor cations generated by the fast atom bombardment (FAB) ionization of N-arachidonylethanolamine (anandamide) and a series of endocannabinoid-like compounds, such as N-oleoylethanolamine, N-palmitoylethanolamine, N-stearoylethanolamine, N-linoleoylethanolamine, N-oleoylpropanolamine, and N-palmitoylpropanolamine, as a method of providing general information on their characterizations was examined. The CID spectra of lithium-adduct [M+Li]+ ions of the amines with unsaturated hydrocarbon chains were rich in structurally informative charge-site-remote (CSR) fragmentation patterns that provide information on the locations of double bonds in hydrocarbon chains. On the other hand, the CID reactions of [M+H]+ ions produced acylium ions that are derived from the cleavage of amide bonds, thus providing information on the size of the hydrocarbon chains, although CSR fragmentations were not observed. These compounds without derivatization were analyzed using gas chromatography/chemical ionization-mass spectrometry (GC/CI-MS) with a polyethylene glycol phased column with fused silica capillary pre-tubing. Identifiable molecular-related [M+H]+ ions were observed. 相似文献
20.
Krishna M. R. Kallury Ulrich J. Krull Micliael Thompson 《Journal of mass spectrometry : JMS》1991,26(2):81-84
The positive and negative FAB mass spectra of a series of alkoxy- and chloro-silanes Xm(CH3)3-mSi(CH2)nR [m = 1 or 3, n = 3, 10 or 17, X = Cl or OMe or OEt, R = Me, NH2, glycidoxy, COOMe, NHCO(CH2)7COOMe or NHCO(CH2)10CH2OAc] were recorded in NBA and NPOE matrices. The chlorosilanes underwent rapid hydrolysis into silanols which condense to form siloxanes, the process being complete in NBA and partial in NPOE, yielding siloxane-based fragment ions in the positive spectra and silyloxyanions in the negative spectra. The alkoxysilanes were more resistant to hydrolysis, affording abundant [MH – HX]+ ions (X = OMe or OEt) in their positive FAB spectra and moderate to high intensity [M – H]? ions in the negative mode, the latter undergoing characteristic sequential loss of C2H4, EtOH and C2H4. Significant variations were observed in the positive spectra of all the silanes with change of matrix. 相似文献