title: Analysis of tetramethylpyrazine in Ephedrae herba by gas chromatography-mass spectrometry and high-performance liquid chromatography.
abstract: A simple and reliable HPLC method was developed for the determination of 2,3,5,6-tetramethylpyrazine (TMP) in Ephedrae herba. Further identification of TMP was achieved using GC-MS. The mobile phase used was methanol-water-35% acetic acid (35:65:0.5, v/v/v) at a flow-rate of 0.8 ml/min. The detection wavelength was set at 290 nm. The linear range of the peak area calibration curve of TMP was 2.64-264 mg/l (r=0.9987) and the recovery for TMP in Ephedrae herba extracts was 101.1-106.9%. The relative standard deviations of retention time and peak area were 0.18 and 1.5% (n=6), respectively. The detection limit of TMP was 0.03 mg/l. The contents of TMP in Ephedrae herba could easily be determined within 10 min.
authors.affiliation: Department of Chemistry, Tsinghua University, Beijing, China.
authors.forename: K
authors.initials: K
authors.lastname: Lv
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Ding
mesh_terms: D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D029790:Ephedra sinica; D004809:Ephedrine / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D028321:Plant Preparations; D011719:Pyrazines / Q000032:analysis*; D029789:Ephedra
chemical_list: D004365:Drugs, Chinese Herbal; D028321:Plant Preparations; D011719:Pyrazines; C099950:Ephedrae herba; D004809:Ephedrine; C017953:tetramethylpyrazine