title: [Sampling in quality control of medicinal materials-A case of Epimedium].
abstract: OBJECTIVE
  To investigate the effect of the different individual number of sampling on the assay results of the medicinal materials.
  
  
  METHODS
  Epimedium pubescens and E. brevicornu were used as samples. The 6 sampling levels were formulated as 1 individual, 5, 10, 20, 30, 50 individuals mix, each level with 3 parallels and 1 individual level5 parallels. The contents of epimedin C and icariin, and the peak areas of epimedin A, epimedin B, rhamnosyl icarisid II and icarisid II in all samples were analyzed by HPLC.
  
  
  RESULTS
  The variation degree varied with species and chemical constituents, but the RSD and the deviation from the true value decreased with the increase of individual number on the same chemical constituent.
  
  
  CONCLUSIONS
  The sampling number should be more than 10 individuals in quality control of Epimedium, and 50 or more individuals would be better for representing the quality of medicinal materials.
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China.
authors.forename: Chuanyi
authors.initials: C
authors.lastname: Wang
authors.forename: Jinyi
authors.initials: J
authors.lastname: Cao
authors.forename: Yun
authors.initials: Y
authors.lastname: Liang
authors.forename: Wenhua
authors.initials: W
authors.lastname: Huang
authors.forename: Baolin
authors.initials: B
authors.lastname: Guo
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D034181:Epimedium / Q000737:chemistry*; D005419:Flavonoids / Q000032:analysis / Q000737:chemistry; D008516:Medicine, Chinese Traditional / Q000379:methods*; D011786:Quality Control; D015203:Reproducibility of Results
chemical_list: D004365:Drugs, Chinese Herbal; D005419:Flavonoids; C529106:epimedin A; C106053:epimedin B; C106054:epimedin C; C060988:baohuoside I