title: [Determination of ephedrine hydrochloride, pseudoephedrine hydrochloride and methylephedrine hydrochloride in maxingshigan decoction by CE].
abstract: OBJECTIVE
  To establish the method for determination of ephedrine hydrochloride, pseudoephedrine hydrochloride and methylephedrine hydrochloride in maxingshigan decoction by capillary electrophoresis.
  
  
  METHODS
  The separation was performed on a fused silica capillary of 60 cm x 55 microcrpm ID (52 cm of effective length). 60 mmol/L NaB4O7 + 10% (V/V) CH3OH (pH 9.0) was selected as the running buffer. The separation voltage was 12 kV. The samples was injected by gravity (10 s, 15 cm). The detection wavelength was 210 nm and berberine hydrochloride was the internal standard.
  
  
  RESULTS
  The linear range of determination for ephedrine hydrochloride, pseudoephedrine hydrochloride and methylephedrine hydrochloride were 20.0-160.0 microg/mL (r = 0.9999), 7.5-60.0 microg/mL (r = 0.9991) and 2.0-10.0 microg/mL (r = 0.9993). The average recoveries were 98.0%, 97.0% and 97.8%, the precisions of the method were 2.31%, 2.21% and 2.00% (n=6), respectively.
  
  
  CONCLUSIONS
  The method is convenient, rapid and accurate for the quality control of maxingshigan decoction.
authors.affiliation: School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China. aleckyu@126.com
authors.forename: Li-ping
authors.initials: LP
authors.lastname: Yu
authors.forename: Xiao-ke
authors.initials: XK
authors.lastname: Wang
authors.forename: Jia-bo
authors.initials: JB
authors.lastname: Luo
mesh_terms: D004365:Drugs, Chinese Herbal / Q000032:analysis / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D029790:Ephedra sinica / Q000737:chemistry; D004809:Ephedrine / Q000031:analogs & derivatives / Q000032:analysis*; D010946:Plants, Medicinal / Q000737:chemistry*; D054199:Pseudoephedrine / Q000032:analysis*; D011786:Quality Control; D015203:Reproducibility of Results
chemical_list: D004365:Drugs, Chinese Herbal; C041707:N-methylephedrine; D054199:Pseudoephedrine; D004809:Ephedrine