Discontinuous electrokinetic chromatography of parabens using different substituted resonances as pseudostationary phases

Bazzanella, A.; Bächmann, K.; Milbradt, Robert; Böhmer, Volker; Vogt, Walter

doi:10.1002/(sici)1522-2683(19990101)20:1<92::aid-elps92>3.0.co;2-4

Cited by 14 publications

(1 citation statement)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This method has been widely applied to separation, enantioseparation and determination of association constants. [28][29][30][31][32] Human serum albumin has been used as a chiral selector to separate many drugs in CE. 19,26,33,34 However, the chiral separation of mexiletine and chlorpheniramine with HSA as selector has not been reported.…”

Section: Introductionmentioning

confidence: 99%

Enantiomeric Separation of Basic Drugs with Partially Filled Serum Albumin as Chiral Selector in Capillary Electrophoresis

Chen

2004

ANAL. SCI.

View full text Add to dashboard Cite

A reliable method is presented for the chiral separation of three basic drugs (mexiletine, chlorpheniramine and propranolol) with serum albumins (human and porcine, HSA and PSA) as chiral selectors by capillary electrophoresis in combination with the partial filling technique. Based on the systematic optimization of operation variables, the chiral separation of mexiletine, chlorpheniramine and propranolol was achieved in the pH 7.4 phosphate buffer by using HSA, PSA and PSA as selectors, respectively. The chiral recognition ability of HSA and PSA was compared. HSA and PSA show a different chiral recognition ability for each of the three drugs. In addition, the association constants between enantiomeric drugs and proteins were determined to be 2.00 and 3.80 × 10 2 M -1 for mexiletine and HSA, 0.59 and 1.12 × 10 3 M -1 for chlorpheniramine and PSA, and 0.87 and 1.42 × 10 3 M -1 for propranolol and PSA. The method for the chiral separation and determination of association constants possesses the advantages of simple performance, effective avoiding of the interference of the UV detection from protein, and lowering of the reagent consumption.

show abstract

Section: Introductionmentioning

confidence: 99%

Enantiomeric Separation of Basic Drugs with Partially Filled Serum Albumin as Chiral Selector in Capillary Electrophoresis

Chen

2004

ANAL. SCI.

View full text Add to dashboard Cite

show abstract

Polymeric and polymer-supported pseudostationary phases in micellar electrokinetic chromatography: Performance and selectivity

Palmer

2000

Electrophoresis

View full text Add to dashboard Cite

Several types of synthetic ionic polymers have been employed as pseudostationary phases in electrokinetic chromatography. The polymers have been shown to have some significant advantages and different chemical selectivity relative to conventional surfactant micelles. Polymeric phases are effective for the separation and analysis of hydrophobic and chiral compounds, and may be useful for the application of mass spectrometric detection. Additionally, the polymeric phases often demonstrate unique selectivity relative to micellar phases, and can be designed and synthesized to provide desired selectivity. This review covers efforts to develop and characterize the performance, characteristics, and selectivity of synthetic polymeric pseudostationary phases since their introduction in 1992. Some ideas for the future development of polymeric pseudostationary phases and the role they may play in electrokinetic separations are presented.

show abstract

Separation of (Z)‐ and (E)‐isomers of thioxanthene and dibenz[b,e]oxepin derivatives with calixarenes and resorcinarenes as additives in nonaqueous capillary electrophoresis

Sokoließ¹,

Gronau²,

Menyes³

et al. 2003

Electrophoresis

View full text Add to dashboard Cite

Five acidic calix[4]arenes with carboxylic or sulfonic groups at either the upper or lower rim of the cavity and one resorc[4]arene were investigated to separate three thioxanthenes (flupentixol, clopenthixol, chlorprothixene) and a dibenz[b,e]oxepin derivative (doxepin) with cis-/trans-isomerism by nonaqueous capillary electrophoresis (NACE). Partial filling of the capillary with the UV-absorbing selectors led to a low detection limit and an advantageous signal-to-noise ratio (S/N). A sufficient electrophoretic mobility of the calixarenes towards the anode was necessary to outweigh the oppositely directed electroosmotic flow (EOF). This depended from the functional groups, the dissociation and the hydrodynamic radius of the cyclophanes. In contrast, the resorcinarene was useable only by addition of sodium dodecyl sulfate (SDS) because only the complex of the two selectors had an anodic apparent electrophoretic mobility. p-Sulfonyl-calix[4]arene (ss-a1) was the most capable selector for all E/Z-isomers with maximal alpha-values ranging from 1.056 for doxepin to 1.224 for chlorprothixene. This was due to the sufficient migration in reversed direction to the EOF even at low pH* values of 3.0. Otherwise, electrostatic as well as hydrophobic interactions with the positively charged isomers seem to contribute to a superior recognition. Increasing the concentration up to 15 mM ss-a1 and using acidic media (pH* 5.0) led to high separation efficiency. Changing the organic solvent provides a powerful tool to improve selectivity with N,N-dimethylformamide-methanol (DMF-MeOH)-mixtures for thioxanthenes. Further electrophoretic parameters were optimized, such as the concentration of the electrolytes, the addition of SDS, the kind of electrolytes and the voltage. Distinct differences in selectivities were found between the derivatives with thioxanthene and dibenzo[b,e]oxepin ring system, respectively. Further, the different basic side chain was responsible for the different selectivity at higher pH* values. In contrast, the substitution at position 2 of the thioxanthenes played a secondary role. Based on the studies of single parameters a method for a simultaneous separation of the four pairs of isomers within 13 min was developed.

show abstract

Discontinuous electrokinetic chromatography of parabens using different substituted resonances as pseudostationary phases

Cited by 14 publications

References 28 publications

Enantiomeric Separation of Basic Drugs with Partially Filled Serum Albumin as Chiral Selector in Capillary Electrophoresis

Enantiomeric Separation of Basic Drugs with Partially Filled Serum Albumin as Chiral Selector in Capillary Electrophoresis

Polymeric and polymer-supported pseudostationary phases in micellar electrokinetic chromatography: Performance and selectivity

Separation of (Z)‐ and (E)‐isomers of thioxanthene and dibenz[b,e]oxepin derivatives with calixarenes and resorcinarenes as additives in nonaqueous capillary electrophoresis

Contact Info

Product

Resources

About