Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Ion spectra

Also in general terms, the TOF part of the hybrid is used mostly for MS/MS studies in which ions produced in the magnetic sector are collided with neutral gas molecules to induce decomposition (see Chapter 23). In this mode the instrument produces more highly resolved product ion spectra than can be attained in simple magnetic-sector instruments. [Pg.157]

Absorption Spectra, of Aqueous Ions. The absorption spectra of Pu(III) [22541-70 ] Pu(IV) [22541 4-2] Pu(V) [22541-69-1] and Pu(VI) [22541-41-9] in mineral acids, ie, HCIO and HNO, have been measured (78—81). The Pu(VII) [39611-88-61] spectmm, which can be measured only in strong alkaU hydroxide solution, also has been reported (82). As for rare-earth ion spectra, the spectra of plutonium ions exhibit sharp lines, but have larger extinction coefficients than those of most lanthanide ions (see Lanthanides). The visible spectra in dilute acid solution are shown in Figure 4 and the spectmm of Pu(VII) in base is shown in Figure 5. The spectra of ions of plutonium have been interpreted in relation to all of the ions of the bf elements (83). [Pg.197]

Figure 3.10 shows the secondary ion spectra recorded from within the defect and its surroundings. The spectrum from the defective area clearly shows the presence of a polluting perfluorinated polyether structure (the C Fy peaks and the peak at mass 47 amu (CFO" ) are diagnostic of the polyether structure). [Pg.98]

Fig. 50. High-resolution positive ion spectra of hd-PE after electrochemical treatment with nitric acid for I min at 60°C in the pre.sence of silver ions. Peak components in order of increasing mass wi/z =43 - C H,0+, C3HI w/z = 57 - CiHsO+, C4H+ wi/z = 71 - CiHiOt, C4H7O+, C5H+ mjz. = 85 - C4HsOt, CsH.)0, C6H/ 3 m/z = 97 - C5H202 CzH/, m /z =111-C6H70t, C7H 0, CsH 5. Reprinted by permission of John Wiley and Sons from Ref. [58]. Fig. 50. High-resolution positive ion spectra of hd-PE after electrochemical treatment with nitric acid for I min at 60°C in the pre.sence of silver ions. Peak components in order of increasing mass wi/z =43 - C H,0+, C3HI w/z = 57 - CiHsO+, C4H+ wi/z = 71 - CiHiOt, C4H7O+, C5H+ mjz. = 85 - C4HsOt, CsH.)0, C6H/ 3 m/z = 97 - C5H202 CzH/, m /z =111-C6H70t, C7H 0, CsH 5. Reprinted by permission of John Wiley and Sons from Ref. [58].
Experimental. The mass spectra in Figures 1-8 are positive-ion spectra produced by electron impact and were obtained from a single-focusing, magnetic deflection Atlas CH4 Mass Spectrometer. The ionizing potential was 70 e.v. and the ionizing current 18/a a. An enamel reservoir heated to 120°C. was used from which the sample was leaked into the ion source. [Pg.217]

Furlei and coworkers44 studied the negative ion mass spectra of several cyclic sulfones (82-98) upon dissociative electron capture and concluded that the negative molecular ions were notably stabilized by the introduction of electron-withdrawing substituents and/or unsaturation. Some difference was found in the negative ion mass spectra of configurational isomers (85 vs. 86 and 87 vs. 88) in contrast to the situation in their positive ion spectra. A strong S02 ion (m/z 64) was observed also for all the compounds studied. [Pg.146]

In what follows we briefly review some of the previous attempts to analyze the available spectra of plutonium (6). In addition, we estimate energy level parameters that identify at least the gross features characteristic of the spectra of plutonium in various valence states in the lower energy range where in most cases, several isolated absorption bands can be discerned. The method used was based on our interpretation of trivalent actinide and lanthanide spectra, and the generalized model referred to earlier in the discussion of free-ion spectra. [Pg.189]

The product-ion spectra of the (M - - H)+ ions of atrazine, the structure of which is shown in Figure 3.29, and three of its transformation products showed that if the isopropyl side-chain was present in the structure a constaut neutral... [Pg.87]

The structure of Bosentan [30] and three of its metabolites are shown in Figure 5.45 and the product-ion spectra from the [M - - H]+ ions from these compounds in Figure 5.46. All show an ion at m/z 280 which might be assumed, simplistically, to share the same structure. Their accurate masses, determined by using a Q-ToF instrument, however, show that the ions from compounds (1)... [Pg.257]

Figure 5.46 Product-ion spectra of (a) Bosentan (1) [M -F H] 552.1917, and its (b) hydroxy metabolite (2) [M + H]+ 568.1866, (c) phenol metabolite (3) [M + H] 538.1760, and (d) hydroxyphenol metabolite (4) [M-FH] 554.1790. Reprinted by permission of Elsevier Science from Exact mass measurement of product ions for the structural elucidation of drug metabolites with a tandem quadrupole orthogonal-acceleration time-of-flight mass spectrometer , by Hopfgartner, G., Chemushevich, I. V., Covey, T., Plomley, J. B. andBonner, K., Journal of the American Society for Mass Spectrometry, Vo. 10, pp. 1305-1314, Copyright 1999 by the American Society for Mass Spectrometry. Figure 5.46 Product-ion spectra of (a) Bosentan (1) [M -F H] 552.1917, and its (b) hydroxy metabolite (2) [M + H]+ 568.1866, (c) phenol metabolite (3) [M + H] 538.1760, and (d) hydroxyphenol metabolite (4) [M-FH] 554.1790. Reprinted by permission of Elsevier Science from Exact mass measurement of product ions for the structural elucidation of drug metabolites with a tandem quadrupole orthogonal-acceleration time-of-flight mass spectrometer , by Hopfgartner, G., Chemushevich, I. V., Covey, T., Plomley, J. B. andBonner, K., Journal of the American Society for Mass Spectrometry, Vo. 10, pp. 1305-1314, Copyright 1999 by the American Society for Mass Spectrometry.
Figure 5.55 MS" spectra from rntz 329, the (M + H)+ ion of an hydroxy metabolite of Praziquantel, and the base peaks in subsequent product-ion spectra. Reprinted from J. Chromatogr., B, 708, Lerch, C. and Blaschke, G., Investigation of the stereoselective metabolism of Praziquantel after incubation with rat liver microsomes by capillary electrophoresis and liquid chromatography-mass spectrometry , 267-275, Copyright (1998), with permission from Elsevier Science. Figure 5.55 MS" spectra from rntz 329, the (M + H)+ ion of an hydroxy metabolite of Praziquantel, and the base peaks in subsequent product-ion spectra. Reprinted from J. Chromatogr., B, 708, Lerch, C. and Blaschke, G., Investigation of the stereoselective metabolism of Praziquantel after incubation with rat liver microsomes by capillary electrophoresis and liquid chromatography-mass spectrometry , 267-275, Copyright (1998), with permission from Elsevier Science.
FD-MS is a very effective technique for determining molecular weights of thermally labile and nonvolatile compounds, such as polymer additives which do not give good molecular ion spectra during electron impact or chemical ionisation [108], In order to enhance the structural information of the technique, MS/MS approaches must be used [96], Hyphenated chromatography-FD/FT-MS techniques appear to be restricted to on-line GC-MS. [Pg.375]

FD-MS is also an effective analytical method for direct analysis of many rubber and plastic additives. Lattimer and Welch [113,114] showed that FD-MS gives excellent molecular ion spectra for a variety of polymer additives, including rubber accelerators (dithiocar-bamates, guanidines, benzothiazyl, and thiuram derivatives), antioxidants (hindered phenols, aromatic amines), p-phcnylenediamine-based antiozonants, processing oils and phthalate plasticisers. Alkylphenol ethoxylate surfactants have been characterised by FD-MS [115]. Jack-son et al. [116] analysed some plastic additives (hindered phenol AOs and benzotriazole UVA) by FD-MS. Reaction products of a p-phenylenediaminc antiozonant and d.v-9-lricoscnc (a model olefin) were assessed by FD-MS [117],... [Pg.375]

ToFs can also be used in combination with other mass analysers. Both hybrid sector and quadrupole systems are available. oaToF-MS has been interfaced to a quadrupole mass filter and hexapole gas collision cell, such as to allow recording of mass spectra and product ion spectra with good mass resolution (ca. 10000), high sensitivity, high mass range (ca. 10 000 Da) and high mass accuracy (<5ppm) [177,178]. QqToFMS may be fitted with API sources with flow-rates from nL... [Pg.392]

Chemical ionisation is the most frequently used ionisation technique in SFC-MS. It provides better sensitivity compared with charge exchange. All standard Cl reagent gases can be used in SFC-MS. In the absence of a modifier, CO2 can act as reagent gas giving real molecular ion spectra (eq. 7.2) ... [Pg.481]

In analyses where molecular masses are being matched, more accurate mass measurements provide more reliable matches and identifications.26,65,66 In a reference laboratory the mass accuracy to several decimal points, provided by a Fourier transform ion cyclotron resonance mass analyzer, may be desirable. In field or portable systems there is usually a trade-off in mass accuracy for size and ruggedness. Reliable identifications can be made with moderate mass accuracy, even 1 Da, if a large enough suite of molecular ions is recorded and used to search the database. If both positive ion and negative ion spectra are... [Pg.262]


See other pages where Ion spectra is mentioned: [Pg.805]    [Pg.240]    [Pg.543]    [Pg.544]    [Pg.95]    [Pg.101]    [Pg.309]    [Pg.309]    [Pg.309]    [Pg.312]    [Pg.1029]    [Pg.47]    [Pg.47]    [Pg.177]    [Pg.197]    [Pg.461]    [Pg.177]    [Pg.297]    [Pg.33]    [Pg.288]    [Pg.28]    [Pg.366]    [Pg.382]    [Pg.382]    [Pg.385]    [Pg.386]    [Pg.395]    [Pg.403]    [Pg.405]    [Pg.543]    [Pg.26]    [Pg.167]    [Pg.266]   
See also in sourсe #XX -- [ Pg.3 , Pg.19 ]




SEARCH



Absorption spectra of ions

Absorption spectra of ions in solution

Absorption spectra of ions solution

Absorption spectra of lanthanide and actinide ions

Actinides ions, absorption spectra

Aromatic hydrocarbon ions mass spectra

Daughter ion spectra

Divalent ions spectra

Electronic spectra lanthanide ions

Emission spectra lanthanide ions

Energy Level Diagrams for the Lanthanide Ions, and their Electronic Spectra

Energy level diagrams and crystal field spectra of transition metal ions

Enolate ions mass spectra

Fluorescence spectra of ions in solution

Fourier transform ion cyclotron resonance mass spectra

Fragment ion mass spectra

Gaseous atoms/ions spectra

Hobbs, R. J. M., Absorption Spectra of Crystals Containing Transition Metal Ions

Ion Detection and Spectra Acquisition

Ion cyclotron resonance mass spectra

Ion energy spectrum

Ion mobility spectra

Ion scattering spectra

Ions in solution absorption spectra

Ions, absorption spectra

MIKE spectra fragments ions

Mass spectrum molecular ion

Mass-analyzed ion kinetic energy spectrum

Negative ion FAB mass spectrum

Negative ion spectra

Negative-Ion Mass Spectra and Electron Affinities

Negative-ion mass spectra

Negative-ion mass spectra of arenesulfonyl chlorides

Negative-ion mass spectra of sulfonamides

Oxonium ions, mass spectra

Pentavalent ions spectra

Polyatomic ions, infrared spectrum

Positive ion FAB mass spectrum

Positive ion spectra

Positive-ion mass spectra

Positive-ion mass spectra of sulfonamides

Product ion mass spectra

Product ion spectrum

Secondary ion mass spectra

Sequence ions, mass spectra

The Dynamics of Ammonium Ions in NMR Spectra

The Ion Mobility Spectrum

The absorption and fluorescence spectra of rare earth ions in solution

The absorption andfluorescence spectra of rare earth ions in solution

Transition metal ions absorption spectra

Trivalent ions spectra

Vibrational Spectra of Arenium Ion Salts

Vibrational spectra osmiamate ion

© 2024 chempedia.info