title: [Harmful elements removal from Polygonum multiflorum by supercritical CO2 extraction].
abstract: OBJECTIVE
  To remove harmful elements as copper, lead and arsenic from Polygonum multiflorum, a Chinese traditional medicine, by supercritical carbon dioxide extraction.
  
  
  METHODS
  With sodium diethyldithiocarbamate (NaDDC) as a chelating agent and ethanol as a modifier, the effects of extraction style, time, pressure, temperature and amount of chelating agent on chelating extraction process were discussed.
  
  
  RESULTS
  The condition was optimized as following: 28 MP as extraction pressure, 60 degrees C as extraction temperature, 1 h as static extraction time, 2 h as dynamic extraction time, m(herb) : m(NaDDC) = 5 : 1, m(herb) : m(ethanol) = 1 : 1. Under this condition, the extraction rate of Cu, Pb and As were up to 60% which achieved US FDA standard, while the physioloically active substance of 2,3,5,4'-tetrahydroxy-silbene-2-O-beta-D-glucoside was not extracted.
  
  
  CONCLUSIONS
  The results show chelating extraction by supercritical CO2 can provide a non-destructive method to decrease the content of harmful elements from Chinese traditional medicines.
authors.affiliation: College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, China. wenzhen1977@163.com
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wen
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.forename: Zong-Kun
authors.initials: ZK
authors.lastname: Zheng
authors.forename: Xin-Kui
authors.initials: XK
authors.lastname: You
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Pu
authors.forename: Zhi
authors.initials: Z
authors.lastname: Dang
mesh_terms: D001151:Arsenic / Q000737:chemistry / Q000378:metabolism; D002245:Carbon Dioxide; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D003300:Copper / Q000737:chemistry / Q000378:metabolism; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification*; D005960:Glucosides / Q000032:analysis; D007854:Lead / Q000737:chemistry / Q000378:metabolism; D010946:Plants, Medicinal / Q000737:chemistry; D019664:Polygonaceae / Q000737:chemistry; D011312:Pressure; D013267:Stilbenes / Q000032:analysis; D013678:Technology, Pharmaceutical / Q000379:methods*; D013696:Temperature
chemical_list: D004365:Drugs, Chinese Herbal; D005960:Glucosides; D013267:Stilbenes; C093026:2,3,5,4'-tetrahydroxystilbene 2-O-glucopyranoside; D002245:Carbon Dioxide; D007854:Lead; D003300:Copper; D001151:Arsenic