Linked Life Data

14753725

Source:http://linkedlifedata.com/resource/pubmed/id/14753725

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2004-2-2
pubmed:abstractText
A coal tar pitch and a petroleum vacuum residue have been separated by TLC using pyridine, acetonitrile, toluene and pentane to develop the chromatograms. The bands of material detected were recovered in 1-methyl-2-pyrrolidinone (NMP) solvent and examined by size-exclusion chromatography (SEC) in NMP eluent. The relation between elution time in SEC and mobility on the TLC plate indicated that molecular size increased steadily with increasing immobility on the plate. This relation was reinforced by UV fluorescence spectroscopy in that the fluorescence moved to longer wavelengths with increasing immobility. The molecular size of the material excluded from the porosity of the SEC column remains undefined; some excluded material was found in all of the fractions from both samples. The valley of zero intensity separating the retained material from the excluded material may suggest a change of structure from near-planar in the retained region to three-dimensional in the excluded region.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9673
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
1024
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
227-43
pubmed:dateRevised
2009-1-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Thin-layer chromatography of pitch and a petroleum vacuum residue. Relation between mobility and molecular size shown by size-exclusion chromatography.
pubmed:affiliation
Department of Chemical Engineering and Chemical Technology, South Kensington Campus, Imperial College London, London SW7 2AZ, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't