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Titolo:
Gas chromatography/mass spectrometry of polyethylene glycol oligomers
Autore:
Onigbinde, A; Nicol, G; Munson, B;
Indirizzi:
Univ Delaware, Dept Chem & Biochem, Newark, DE 19716 USA Univ Delaware Newark DE USA 19716 pt Chem & Biochem, Newark, DE 19716 USA
Titolo Testata:
EUROPEAN JOURNAL OF MASS SPECTROMETRY
fascicolo: 3, volume: 7, anno: 2001,
pagine: 279 - 291
SICI:
1469-0667(2001)7:3<279:GCSOPG>2.0.ZU;2-A
Fonte:
ISI
Lingua:
ENG
Soggetto:
IONIZATION MASS-SPECTROMETRY; ELECTROSPRAY IONIZATION; POLY(ETHYLENE GLYCOL); SELECTIVE REAGENTS; GENERAL SCHEME; ORGANIC IONS; ALCOHOLS; SPECTRA; TETRAMETHYLSILANE; POLYGLYCOLS;
Keywords:
GC/EIMS; GC/CIMS; PEG oligomers; ion molecule reactions; relative molar sensitivities; low voltage EIMS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
47
Recensione:
Indirizzi per estratti:
Indirizzo: Munson, B Univ Delaware, Dept Chem & Biochem, Newark, DE 19716 USA Univ Delaware Newark DE USA 19716 Biochem, Newark, DE 19716 USA
Citazione:
A. Onigbinde et al., "Gas chromatography/mass spectrometry of polyethylene glycol oligomers", EUR J MASS, 7(3), 2001, pp. 279-291

Abstract

Polyethylene glycol (PEG) oligomers, H(OC2H4O)(n)H, were analyzed by gas chromatography/mass spectrometry (GC/MS) for oligomers, n = 2-11, without indications of pyrolysis of the higher oligomers at oven temperatures of 330 degreesC. The electron ionization (EI) mass spectra (70 eV and 12-14 eV) ofthese PEG oligomers contain only low molecular weight fragment ions and, essentially, no M+ ions. The low-voltage El spectra contain more abundant high mass ions and allow easier identification of the PEG oligomers. The major fragment ions in all EI spectra are (C2H4O)(x)H+ at m/z 45, 89, 133 and 177. The base peak in the low-voltage spectra varies with molecular weight and suggests preferential cleavage at the second and third ether linkages. The relative molar sensitivities (70 eV EI) of PEG oligomers (n = 1-6) are linear functions of molecular weight or polarizability ratios. The CH4 chemical ionization mass spectra of the PEG oligomers contain, predominantly, (C2H4O)(x)H+ ions at m/z 45, 89,133 and 177. The relative abundances of MH+ ions vary markedly across the chromatographic peaks because these ions are formed predominantly by sample ion/sample molecule reactions. Proton transfer reactions from CH5+ and C2H5+ to the PEG oligomers are almost entirely dissociative. The i-C4H10 CI mass spectra of PEG oligomers contain MH+ as thebase peaks. The relative abundances of MH+ ions do not vary significantly across the chromatographic peaks but do increase with increasing pressure of i-C4H10. The extent of decomposition of MH+ ions in i-C4H10 CI mass spectra increases with increasing molecular weight of the PEG oligomers. Relative molar sensitivities (CH4CI and i-C4H10CI) of PEG oligomers (n = 1-6) are essentially the same linear functions of molecular weight ratio.

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Documento generato il 03/04/20 alle ore 04:29:33