Poly(ethyleneglycol) in electrospray ionization (ESI) mass spectrometry

Varray, S.; Aubagnac, Jean‐Louis; Lamaty, Frédéric; Lázaro, R.; Martinez, Jean; Enjalbal, Christine

doi:10.1051/analusis:2000280263

Cited by 27 publications

(26 citation statements)

References 11 publications

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“…As evident in Figure 3, the highest APPI(Ϫ)-MS intensity with increasing toluene concentration can be obtained using CCl 4 . No dopant is necessary with CH 2 Cl 2 , albeit the intensity slightly increases with tol- uene concentration.…”

Section: Appi-ms In the Negative Ion Mode (Appi(ϫ)-ms)mentioning

confidence: 74%

“…Nevertheless the solvent does have an effect. In CCl 4 and CHCl 3 , fragmentation with R ϭ ϳ0.15 and ϳ0.18, respectively, can be observed. However, the highest extent of fragmentation was found in CH 2 Cl 2 (R ϭ ϳ0.4).…”

Section: Appi-ms In the Negative Ion Mode (Appi(ϫ)-ms)mentioning

confidence: 97%

“…The positive APPI-MS spectra of HO-PIB-OH, ϭ -PIB-ϭ and PIB-OH (see Scheme 1), which were obtained in tetrahydrofuran, hexane, and chlorinated solvents such as CCl 4 However, the most probable peak appeared at m/z values (ϳm/z 1500 -1600) that were considerably lower than expected on the basis of their M n values (ϳm/z 2000) and relative narrow polydispersity (a representative APPI(ϩ)-MS spectrum is shown in the Supplementary Material, which can be found in the electronic version of this article). In addition, the obtained APPI(ϩ)-MS intensity distribution of PIBs is skewed to the lower m/z range.…”

Section: Appi-ms In the Positive Ion Mode (Appi(ϩ)-ms)mentioning

confidence: 99%

“…The number densities of the toluene molecules were simply calculated by considering the sample flow rate (25 L/min), the actual toluene-content of the sample flow, as well as the total volumetric flow (3 L/min). Figure 5 shows the experimental and calculated plots for the variations of signal intensities on the toluene concentrations for ϭ -PIB-ϭ in CCl 4 . The rate constants used to calculate the plot presented in Figure 5 are summarized in Table 1.…”

Section: Mechanistic and Kinetic Considerations Of Chlorinated Adductmentioning

confidence: 99%

“…This is more pronounced as the polarity of the polymers decreases. For example, mass spectrometric analysis of polar polymers such as polyethylene glycol (PEG) and polypropylene glycol (PPG) can easily be achieved using MALDI and/or ESI [3][4][5][6][7][8][9][10]. Nonpolar polymers such as polystyrenes are also amenable to MALDI and ESI through the formation of silver-or copper-cationized adduct ions [11][12][13][14].…”

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confidence: 99%

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Atmospheric pressure photoionization mass spectrometry of polyisobutylene derivatives

Kéki

Török

Nagy

et al. 2008

J. Am. Soc. Mass Spectrom.

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Atmospheric pressure photoionization mass spectrometric (APPI-MS) study on three types of polyisobutylene derivatives is reported. Two of the polyisobutylenes investigated were polyisobutylene with dihydroxy and diolefinic end-groups derived from aromatic moieties [dicumyl chloride, 1,4-bis(2-chloro-2-propyl)benzene], and the third contained no aromatic moieties with a monohydroxy end-group. All three polyisobutylene derivatives (PIBs) had an average molecular weight (M n ) of ϳ2000 g/mol, with a polydispersity lower than 1.2. In the positive ion APPI mode, protonated PIB molecules were formed, but the molecular weights obtained were considerably lower than those expected, indicating fragmentation of the PIB chains. In the negative APPI mode, using solvents such as tetrahydrofuran and toluene as dopants, no signal was obtained. However, in chlorinated solvents, such as CCl 4 , CHCl 3 , and CH 2 Cl 2 , in the presence of toluene dopant, PIB adducts with chloride ions were formed with relatively high signal intensity. In the case of CH 2 Cl 2 , no dopant (toluene) was necessary to generate chlorinated adduct ions, albeit increasing the toluene concentration in the flow increased the PIB signal intensity. The effect of the toluene concentration on PIB signal intensity was studied and models that include (1) photoionization of toluene, (2) formation of chloride ions from the chlorinated solvents by dissociative electron capture, (3) formation of chlorinated adduct ions and charge recombination reactions between the toluene radical cation, (4) chloride ions, and (5) olymer characterization, including the determination of molar mass, molar mass distribution, the mass of the repeat unit and end-groups, and functionality, is an important process that can be accomplished using several methods. Mass spectrometric methods, particularly those that utilize soft-ionization techniques, e.g., matrix-assisted laser desorption/ionization (MALDI) [1,2] or electrospray ionization (ESI) [3], are superior to other methods because they offer a unique capability to determine all of these parameters. Contrary to other spectroscopic methods, such as nuclear magnetic resonance (NMR), which can only determine an average value of some of the above parameters [e.g., the number-average molecular weight (M n ) and number average-functionality (F n )], mass spectrometric methods provide not only these average values, but the individual intact polymer molecules can also be detected. However, because soft-ionization is based on forming adduct ions with metal ions, e.g., alkali or silver ions or through protonation and/or deprotonation, mass spectrometric analysis of polymers having moieties that are unable to form ions presents difficulties. This is more pronounced as the polarity of the polymers decreases. For example, mass spectrometric analysis of polar polymers such as polyethylene glycol (PEG) and polypropylene glycol (PPG) can easily be achieved using . Nonpolar polymers such as polystyrenes are also amenable to MALDI and ESI through the f...

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Section: Appi-ms In the Negative Ion Mode (Appi(ϫ)-ms)mentioning

confidence: 74%

Section: Appi-ms In the Negative Ion Mode (Appi(ϫ)-ms)mentioning

confidence: 97%

Section: Appi-ms In the Positive Ion Mode (Appi(ϩ)-ms)mentioning

confidence: 99%

Section: Mechanistic and Kinetic Considerations Of Chlorinated Adductmentioning

confidence: 99%