title: [Removal of cadmium from extracts of Gentianae Radix et Rhizoma by gamma-mercaptopropyl-modified silica gel].
abstract: OBJECTIVE
  To study the optimum process of removing cadmium irons from extracts of Gentianae Radix et Rhizoma with gamma-mercaptopropyl-modified silica gel (MPS) and assess its cadmium ion-removing property.
  
  
  METHODS
  Static and dynamic adsorptions were adopted to detect the cadmium-removing rate. MPS' cadmium ion-removing property was assessed with such indicators as the cadmium-removing rate, the solid content and the HPLC fingerprint.
  
  
  RESULTS
  The process parameters of the static adsorption were as follows: 0.20 g x mL(-1) of concentration of extracts, 120 minutes of adsorption time and 15:1 between raw materials and MPS. The process parameters of the dynamic adsorption were as follows: 1:3.5 times between diameter and height, 0.20 g x mL(-1) of concentration of extracts, 0.9 mL x min(-1) of flow rate of the extracts and 50:1 between raw materials and MPS. Before and after the cadmium ion-removing process, the extracts showed no notable difference in solid content and HPLC fingerprint.
  
  
  CONCLUSIONS
  gamma-mercaptopropyl-modified silica gel (MPS) can effectively remove cadmium ion from the extracts of Gentianae Radix et Rhizoma with an excellent cadmium ion-removing property.
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
authors.forename: Liang-mian
authors.initials: LM
authors.lastname: Chen
authors.forename: Cai-zhi
authors.initials: CZ
authors.lastname: Kuang
authors.forename: Hui-min
authors.initials: HM
authors.lastname: Gao
authors.forename: Qi-wei
authors.initials: QW
authors.lastname: Zhang
authors.forename: Zhi-min
authors.initials: ZM
authors.lastname: Wang
authors.forename: Jing-jing
authors.initials: JJ
authors.lastname: Zhu
authors.forename: Yan-qing
authors.initials: YQ
authors.lastname: Lu
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000737:chemistry*; D004340:Drug Contamination; D029965:Gentianaceae / Q000737:chemistry*; D027343:Rhizome / Q000737:chemistry*; D058428:Silica Gel / Q000737:chemistry*
chemical_list: D002104:Cadmium; D058428:Silica Gel