title: High-performance liquid chromatographic determination of phenolic compounds in rice.
abstract: A method has been developed for the determination of 6'-O-feruloylsucrose, 6'-O-sinapoylsucrose, ferulic acid, sinapinic acid, p-coumaric acid, chlorogenic (3-caffeoylquinic) acid, caffeic acid, protocatechuic acid, hydroxybenzoic acid, vanillic acid, and syringic acid in rice. The rice samples were extracted with 70% ethanol, filtered, and defatted. The defatted aqueous solution was subjected to solid-phase extraction using a C18 silica gel cartridge; no analyte was lost in this procedure. The 70% acidic methanol elution was analyzed directly by HPLC and HPLC-ESI-MS. Phenolic compounds were separated with a C18 reversed-phase column by gradient elution using 0.025% trifluoroacetic acid in purified water (A)--acetonitrile (B) (0 min, 5% B; 5 min, 9% B; 15 min, 9% B; 22 min, 11% B; and 38 min, 18% B) as the mobile phase at a flow rate of 0.8 ml/min. Detection limits ranged from 0.10 to 0.35 ng per injection (5 microl). Relative standard deviations of 0.22-3.95% and recoveries of 99-108% were obtained for simultaneous determination of these phenolic compounds. This method was applied to analysis of phenolic compounds in brown rice and germinated brown rice soaked in 32 degrees C water for varying durations.
authors.affiliation: Department of Science of Biological Resources, United Graduate School of Agricultural Sciences, Gifu University, Gifu 501-1193, Japan.
authors.forename: Su
authors.initials: S
authors.lastname: Tian
authors.forename: Kozo
authors.initials: K
authors.lastname: Nakamura
authors.forename: Tong
authors.initials: T
authors.lastname: Cui
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kayahara
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D012275:Oryza / Q000737:chemistry*; D010636:Phenols / Q000032:analysis*; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D010636:Phenols