Titre du document / Document title

Capillary electrophoretic studies on the migration behavior of cationic solutes and the influence of interactions of cationic solutes with sodium dodecyl sulfate on the formation of micelles and critical micelle concentration

Auteur(s) / Author(s)

LIN Ching-Erh ⁽¹⁾ ; FANG I-Ju ⁽¹⁾ ; DENG Yan-Jr ⁽¹⁾ ; LIAO Wei-Ssu ⁽¹⁾ ; CHENG Hsu-Tun ⁽¹⁾ ; HUANG Wen-Ping ⁽¹⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Department of Chemistry, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei 10674, TAIWAN, PROVINCE DE CHINE

Résumé / Abstract

The migration behavior of cationic solutes and influences of the interactions of cationic solutes with sodium dodecyl sulfate (SDS) on the formation of micelles and its critical micelle concentration (CMC) were investigated by capillary electrophoresis at neutral pH. Catecholamines and structurally related compounds, including epinephrine, norepinephrine, dopamine, norephedrine, and tyramine, which involve different extents of hydrophobic, ionic and hydrogen-bonding interactions with SDS surfactant, are selected as cationic solutes. The dependence of the effective electrophoretic mobility of cationic solutes on the concentration of surfactant monomers in the premicellar region provides direct evidence of the formation of ion-pairs between cationic solutes and anionic dodecyl sulfate monomers. Three different approaches, based on the variations of either the effective electrophoretic mobility or the retention factor as a function of surfactant concentration in the premicellar and micellar regions, and the linear relationship between the retention factor and the product of a distribution coefficient and the phase ratio, were considered to determine the CMC value of SDS micelles. The suitability of the methods used for the determination of the CMC of SDS with these cationic solutes was discussed. Depending on the structures of cationic solutes and electrophoretic conditions, the CMC value of SDS determined varies in a wide concentration range. The results indicate that, in addition to hydrophobic interaction, both ionic and hydrogen-bonding interactions have pronounced effects on the formation of SDS micelles. Ionic interaction between cationic solutes and SDS surfactant stabilizes the SDS micelles, whereas hydrogen-bonding interactions weakens the solubilization of the attractive ionic interaction. The elevation of the CMC of SDS depends heavily on hydrogen-bonding interactions between cationic solutes and SDS surfactant. Thus, the CMC value of SDS is remarkably elevated with catecholamines, such as epinephrine and norepinephrine, as compared with norephedrine. In addition, the effect of methanol content in the sample solution of these cationic solutes on the CMC of SDS was also examined.

Revue / Journal Title

Journal of chromatography   ISSN 0021-9673   CODEN JOCRAM 

Source / Source

Congrès
HPCE 2004 International Symposium on Microscale Separations and Capillary Electrophoresis N^o17, Salzburg , AUTRICHE (08/02/2004)
2004, vol. 1051, n^o 1-2 (322 p.)  [Document : 10 p.] (38 ref.), pp. 85-94 [10 page(s) (article)]

Langue / Language

Anglais

Editeur / Publisher

Elsevier, Amsterdam, PAYS-BAS  (1958) (Revue)

Mots-clés anglais / English Keywords

Biogenic amine ; Catecholamine ; Intermolecular interaction ; Molecular interaction ; Micellar critical concentration ; Surface properties ; Anionic surfactant ; Ion pair ; Micellization ; Phase composition ; Mobile phase ; Capillary electrophoresis ; Electrophoretic mobility ;

Mots-clés français / French Keywords

Sodium sulfate(lauryl) ; Amine biogène ; Catécholamine ; Interaction intermoléculaire ; Interaction moléculaire ; Concentration critique micellaire ; Propriété surface ; Agent surface anionique ; Paire ion ; Micellisation ; Composition phase ; Phase mobile ; Electrophorèse capillaire ; Mobilité électrophorétique ;

Mots-clés espagnols / Spanish Keywords

Amina biógena ; Catecolamina ; Interacción intermolecular ; Interacción molecular ; Concentración crítica micelar ; Propiedad superficie ; Agente superficie aniónico ; Par ión ; Micelización ; Composición fase ; Fase móvil ; Electroforesis capilar ; Movilidad electroforética ;

Mots-clés d'auteur / Author Keywords

Critical micelle concentration ; Capillary electrophoresis ; Micellization ; Sodium dodecyl sulfate ; Catecholamines ; Cationic solutes ;

Localisation / Location

INIST-CNRS, Cote INIST : 8577 A, 35400012043023.0100