Linked Life Data

14604109

Source:http://linkedlifedata.com/resource/pubmed/id/14604109

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2003-11-7
pubmed:abstractText
Complementary on-line preconcentration strategies are needed when analyzing different classes of solutes in real samples by capillary electrophoresis (CE) with UV detection. The performance of three different on-line preconcentration (focusing) techniques under alkaline conditions was examined in terms of their selectivity and sensitivity enhancement for a group of steroids, including classes of androgens, corticosteroids and estrogens. Electrokinetic focusing of large sample injection plugs (up to 28% of effective capillary length or 22.1 cm) directly on-capillary can be tuned for specific classes of steroids based on changes in their mobility (velocity) using a multi-section electrolyte system in CE. A dynamic pH junction was applied for the selective resolution and focusing of weakly acidic estrogens using borate, pH 11.0 and pH 8.0 in the background electrolyte and the sample, respectively. Sweeping, using an anionic bile acid surfactant and neutral gamma-cyclodextrin (gamma-CD) under alkaline conditions (pH 8), resulted in focusing and separation of the moderately hydrophobic (non-ionic) classes of steroids, such as androgen and corticosteroids. Optimal focusing and resolution of all test steroids under a single buffer condition was realized by a dynamic pH junction-sweeping format using borate, pH 11.0 and bile acid surfactant with gamma-CD in the BGE, whereas the sample is devoid of surfactant at pH 8.0. The design of selective on-line focusing strategies in CE is highlighted by the analysis of microgram amounts of ethynyl estradiol derived from a female contraceptive pill extract using the dynamic pH junction method, which resulted in over a 100-fold enhancement in concentration sensitivity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9673
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
1013
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
65-76
pubmed:dateRevised
2009-1-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Complementary on-line preconcentration strategies for steroids by capillary electrophoresis.
pubmed:affiliation
Graduate School of Science, Himeji Institute of Technology, Kamigori, Hyogo 678-1297, Japan. britz@mcmaster.ca
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't