Determination of the enantiomeric impurity in 1R,2S-ephedrine and S-timolol by chiral ion-pair non-aqueous capillary electrophoresis
2007 (English)In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1141, 287-294 p.Article in journal (Refereed) Published
1S,4R-(+)-ketopinic acid [(+)-KPA] has been introduced as a chiral selector for the separation of pharmacologically active amines by non-aqueouscapillary electrophoresis (NACE). (+)-KPA gave enantioresolution for most of the compounds previously separated by 2R,3S,4R,5S-(−)-2,3:4,6-di-O-isopropylidene-2-keto-l-gulonic acid [(−)-DIKGA], but with a reversed migration order. A complete enantioresolution (Rs = 4.2) was obtainedfor timolol, a compound that could not be resolved using (−)-DIKGA as the selector. Thus, (+)-KPA was evaluated for the enantiomeric puritydetermination of S-timolol. A method based on pre-concentration by transient isotachophoresis (tITP) provided a limit of detection (LOD) of0.2% R-timolol in S-timolol samples. Because of the lack of enantioresolution of ephedrine when (+)-KPA was used as the selector, a methodwith (−)-DIKGA has been developed and validated for determination of the enantiomeric purity of the 1R,2S enantiomer. The method gave goodprecision and accuracy with an LOD (S/N = 3) of 0.033% for the enantiomeric impurity 1S,2R-ephedrine.
Place, publisher, year, edition, pages
Elsevier, 2007. Vol. 1141, 287-294 p.
Diisoproylideneketogulonic acid; Enantiomeric purity; Ephedrine; Ketopinic acid; Timolol; Non-aqueous capillary electrophoresis
IdentifiersURN: urn:nbn:se:uu:diva-94281DOI: 10.1016/j.chroma.2006.12.013OAI: oai:DiVA.org:uu-94281DiVA: diva2:168077