title: Two-dimensional high-performance liquid chromatographic system for the direct determination of tocopherol derivatives in plasma.
abstract: A procedure for the quantitative extraction of tocopherol derivatives from plasma was systematically developed using an efficient liquid-liquid distribution process. An aqueous stationary phase was coated on silica gel or diatomaceous earth powder in a closed-bed glass column prepared by slurry packing. A liquid-liquid chromatographic system provided with a detector was introduced as a preliminary extraction process. Liquid-solid chromatography followed as the second dimension of the separation and was used to determine alpha-tocopherol nicotinate in the extract. Stationary and mobile phases in the two-dimensional liquid chromatographic system were optimized to determine tocopherol derivatives. A highly sensitive quantitation method for alpha-tocopherol nicotinate in plasma was developed by using liquid-liquid and liquid-solid chromatography in conjunction with column switching by a tube-type micro-evaporator.
authors.affiliation: Central Research Laboratory, Nisshin Flour Milling Co., Ltd., Saitama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ijitsu
authors.forename: M
authors.initials: M
authors.lastname: Ueno
authors.forename: S
authors.initials: S
authors.lastname: Hara
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004285:Dogs; D005215:Fasting; D006801:Humans; D013056:Spectrophotometry, Ultraviolet; D014810:Vitamin E / Q000031:analogs & derivatives / Q000097:blood*
chemical_list: D014810:Vitamin E