title: Separation and determination of ephedrine alkaloids and tetramethylpyrazine in Ephedra sinica Stapf by gas chromatography-mass spectrometry.
abstract: A simple, sensitive, and reliable method using gas chromatography (GC)-mass spectrometry (MS) is developed for the simultaneous determination of ephedrine alkaloids and 2,3,5,6-tetramethylpyrazine (TMP) in Ephedra sinica Stapf. The sample is extracted with ethyl ether and submitted to GC-MS for identification and quantitation without derivatization. The column used for GC is an HP-5 (30.0 m x 250 microm x 0.25 microm, 5% phenyl methyl siloxane), and the carrier gas is helium. The detection limits for ephedrine, pseudoephedrine, and TMP are 0.4 ng 0.7 ng, and 0.02 ng (signal-to-noise ratio of 3), respectively. The reproducibility of the total procedure is proved to be acceptable (RSD < 2%), and the recoveries are above 93%.
authors.affiliation: Tsinghua University, Beijing, China.
authors.forename: H X
authors.initials: HX
authors.lastname: Li
authors.forename: M Y
authors.initials: MY
authors.lastname: Ding
authors.forename: K
authors.initials: K
authors.lastname: Lv
authors.forename: J Y
authors.initials: JY
authors.lastname: Yu
mesh_terms: D004809:Ephedrine / Q000032:analysis* / Q000302:isolation & purification; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006371:Helium; D010665:Phenylpropanolamine / Q000032:analysis* / Q000302:isolation & purification; D010936:Plant Extracts / Q000032:analysis; D010946:Plants, Medicinal / Q000737:chemistry*; D011719:Pyrazines / Q000032:analysis* / Q000302:isolation & purification; D011786:Quality Control; D015203:Reproducibility of Results
chemical_list: D010936:Plant Extracts; D011719:Pyrazines; D006371:Helium; C005331:norpseudoephedrine; D010665:Phenylpropanolamine; D004809:Ephedrine; C017953:tetramethylpyrazine