title: Achiral liquid chromatography with circular dichroism detection for the determination of carnitine enantiomers in dietary supplements and pharmaceutical formulations.
abstract: A simple and enantioselective method for the separation and determination of carnitine enantiomers in dietary supplements and pharmaceutical formulation samples is proposed. This method is based on achiral liquid chromatographic separation of carnitine enantiomers from interferences and direct circular dichroism (CD) detection. The calibration curve of the anisotropy factor (g) versus the enantiomeric excess was linear, with a correlation coefficient (R(2)) of 0.996. The precision evaluated by UV peak area and CD peak area was suitable (RSD <5% in all cases). The usefulness of the proposed method was demonstrated by analysing natural dietary supplements and pharmaceutical formulation samples. This method has the advantages of being rapid and precise, without using an expensive chiral column. The method was suitable for the simultaneous determination of both enantiomers and for assessing the chemical purity of carnitine.
authors.affiliation: Department of Analytical Chemistry and Food Technology, Faculty of Chemistry, University of Castilla-La Mancha, Av. Camilo José Cela, 10. E-13004 Ciudad Real, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: de Andrés
authors.forename: Gregorio
authors.initials: G
authors.lastname: Castañeda
authors.forename: Angel
authors.initials: A
authors.lastname: Ríos
mesh_terms: D002021:Buffers; D002138:Calibration; D002214:Capsules; D002331:Carnitine / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D002853:Chromatography, Liquid / Q000379:methods*; D002942:Circular Dichroism / Q000379:methods*; D019587:Dietary Supplements / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000737:chemistry; D012015:Reference Standards; D012996:Solutions / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013237:Stereoisomerism; D013607:Tablets; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D002021:Buffers; D002214:Capsules; D004364:Pharmaceutical Preparations; D012996:Solutions; D013607:Tablets; D014867:Water; D002331:Carnitine