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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2003-9-23
pubmed:abstractText
Quantitativeness of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) was elucidated using an equimolar mixture of uniform poly(ethylene glycol) (PEG) oligomers with no molecular weight distributions. Uniform PEG oligomers with degrees of polymerization n = 6-40 were separated from commercial PEG samples by preparative super-critical fluid chromatography. MALDI-TOF mass spectra of an equimolar mixture of the uniform PEG oligomers were recorded by adding a mixture of 2,5-dihydroxybenzoic acid as a matrix reagent and four chlorinated salts, i.e. LiCl, NaCl, KCl and RbCl. Remarkable non-quantitative effects were observed in the MALDI-TOF mass spectra in both the lower and higher molecular mass regions. At higher molecular masses greater than about 10(3), PEG oligomers with larger molecular mass yielded lower spectral intensities irrespective of the species of adduct cations and higher laser powers induced larger decreases in mass spectral intensities with the increase in their molecular masses. On the other hand, in the lower molecular mass region, less than about 10(3), the observed non-quantitative effect greatly depends on the species of adduct cations, indicating that the stability of the PEG-cation complex affects the MALDI-TOF mass spectral intensities of uniform PEG oligomers.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Sep
pubmed:issn
1076-5174
pubmed:author
pubmed:copyrightInfo
Copyright 2003 John Wiley & Sons, Ltd.
pubmed:issnType
Print
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
948-54
pubmed:year
2003
pubmed:articleTitle
Evaluation of the quantitativeness of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using an equimolar mixture of uniform poly(ethylene glycol) oligomers.
pubmed:affiliation
National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan. k-shimada@aist.go.jp
pubmed:publicationType
Journal Article