title: Simultaneous analysis of tea catechins, caffeine, gallic acid, theanine and ascorbic acid by micellar electrokinetic capillary chromatography.
abstract: A micellar electrokinetic capillary chromatography (MEKC) method for the simultaneous analysis of five tea catechins, theanine, caffeine, gallic acid and ascorbic acid has been developed. The catechins are (-)-epicatechin, (+)-catechin, (-)-epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate. p-Nitrophenol serves as both reference and internal standard. All the components are separated within 13 min with a 57 cm uncoated fused-silica column. On-column detection was carried out at 200 nm. This method has been used to measure these compounds in fresh tea leaves and tea liquor. The limit of detection for all analytes ranged from 1 to 20 microg/ml.
authors.affiliation: Department of Biochemistry, University of Pretoria, South Africa.
authors.forename: J P
authors.initials: JP
authors.lastname: Aucamp
authors.forename: Y
authors.initials: Y
authors.lastname: Hara
authors.forename: Z
authors.initials: Z
authors.lastname: Apostolides
mesh_terms: D001205:Ascorbic Acid / Q000302:isolation & purification*; D002110:Caffeine / Q000302:isolation & purification*; D002392:Catechin / Q000302:isolation & purification*; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D005707:Gallic Acid / Q000302:isolation & purification*; D005971:Glutamates / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D010710:Phosphates / Q000737:chemistry; D015203:Reproducibility of Results; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry; D013662:Tea / Q000737:chemistry*
chemical_list: D005971:Glutamates; D010710:Phosphates; D013501:Surface-Active Agents; D013662:Tea; D012967:Sodium Dodecyl Sulfate; D002110:Caffeine; D005707:Gallic Acid; C026166:theanine; D002392:Catechin; D001205:Ascorbic Acid