title: Steam distillation-solid-phase microextraction for the detection of Ephedra sinica in herbal preparations.
abstract: A new method involving concurrent solid-phase microextraction combined with continuous hydrodistillation of essential oil was developed. This new methodology allowed for the detection by GC-MS of very small amounts of a diagnostic peak for the authentication of Ephedra sinica, in a short period of time and using only small sample sizes. This diagnostic peak was identified as 4-vinylanisole, and elucidated from the chromatographic profile allowed for the identification of a sample as E. sinica among other species investigated in this study. To the best of our knowledge this is the first report on using continuous solid-phase microextraction coupled to hydrodistillation for the investigation of essential oil components, and the first report of 4-vinylanisole as a marker compound for E. sinica. A total of 46 collections representing 21 species of Ephedra were studied.
authors.affiliation: Natural Products Utilization Research Unit, US Department of Agriculture, Agricultural Research Service, Box 8048, Oxford, MS 38677, USA. matellez@ars.usda.gov
authors.forename: Mari R
authors.initials: MR
authors.lastname: Tellez
authors.forename: Ikhlas A
authors.initials: IA
authors.lastname: Khan
authors.forename: Brian T
authors.initials: BT
authors.lastname: Schaneberg
authors.forename: Sara L
authors.initials: SL
authors.lastname: Crockett
authors.forename: Agnes M
authors.initials: AM
authors.lastname: Rimando
authors.forename: Mozaina
authors.initials: M
authors.lastname: Kobaisy
mesh_terms: D001331:Automation; D029790:Ephedra sinica; D029001:Herbal Medicine; D009822:Oils, Volatile / Q000302:isolation & purification; D014867:Water
chemical_list: D009822:Oils, Volatile; D014867:Water