Linked Life Data

9341054

Source:http://linkedlifedata.com/resource/pubmed/id/9341054

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
1997-10-20
pubmed:abstractText
We report a polymer characterization study by matrix-assisted laser description/ionization (MALDI) on a linear time-of-flight instrument equipped with pulsed ion extraction for time-lag focusing. It is demonstrated that time-lag focusing MALDI provides improved mass resolution and mass accuracy over continuous extraction instruments. Oligomer resolution is extended to a much higher mass range than that observed even by continuous extraction reflectron systems. This allows new opportunities to study the chemical composition and determine the molecular weight of individual components in a mixture of higher molecular weight polymers. It is shown that oligomer resolution can be obtained for poly(ethylene glycol) (repeat unit mass of 44) of mass up to 25,000 u and poly(styrene) (repeat unit mass of 104) up to 55,000 u. Mass measurement accuracy of 80 ppm or better is demonstrated, and the relevance to end-group analysis is shown for two derivative of poly(ethylene glycol) used as slow-release drugs. The analysis of the molecular weight distribution was investigated at several extraction pulse potentials to determine if there was an effect on the relative peak area. We found that the values of the number-average molecular weight (Mn and the weight-average molecular weight (Mw) do not change significantly for a poly(styrene) blend with oligomer masses between 2,000 and 15,000 u and a polydispersity of 1.155. The values are within the 1.6% standard deviation observed for repeat analyses at the same extraction pulse.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0003-2700
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
69
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2734-41
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Time-lag focusing MALDI time-of-flight mass spectrometry for polymer characterization: oligomer resolution, mass accuracy, and average weight information.
pubmed:affiliation
Department of Chemistry, University of Alberta, Edmonton, Canada.
pubmed:publicationType
Journal Article