title: [Comparison between the post-column derivatization with bromine by HPLC and the fluorometric analysis for determination of aflatoxins in medicinal herbs and plant extracts].
abstract: OBJECTIVE
  To compare the post-column derivatization technique (IAC-PCD-HPLC) for the determination of aflatoxins B1, B2, G1 and G2 and the rapid procedure with fluorometric analysis (SFB) for the determination of total aflatoxins.
  
  
  METHODS
  The method of post-column derivatization with bromine by HPLC consisted of extraction of the sample with MeOH-H2O (70:30) followed by clean-up of the extracts with immunoaffinity columns and finally, HPLC determination with fluorescence detection. Aflatoxins B1 and G1 were determined as their bromine derivatives, produced in an on-line post-column derivatization system. In SFB method, samples were ground and extracted with methanol-water (70:30). A portion of the extract was cleaned up by passage through a immunoaffinity column, One mL of purified extract was derivatized with a bromine reagent, and fluorescence of the solution was immediately quantified with a calibrated fluorometer containing a broad wavelength pulsed xenon light source.
  
  
  RESULTS
  In IAC-HPLC method, the overall average recoveries for three different medicinal herbs spiked at levels of 1.3 and 2.6 ng x g(-1) of total aflatoxins ranged from 93% to 97%. The detection limit was 0. 06 microg x kg(-1) for both G2 and B2 and 0.20 microg x kg(-1) for both G1 and B1, based on a signal/noise 3:1 and the precision (within-laboratory relative standard deviation) ranged from 0.8% to 1.4%. Each of aflatoxins B1, B2, G1 and G2 in 39 kind medicinal materials were determined by IAC-PCD-HPLC, and the total aflatoxins were determined by SFB.
  
  
  CONCLUSIONS
  The SFB method is not the suitable method for the determination of total aflatoxins in medicinal herbs and plant extracts.
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100094, China.
authors.forename: Xue-hui
authors.initials: XH
authors.lastname: Zhang
authors.forename: Jian-min
authors.initials: JM
authors.lastname: Chen
mesh_terms: D016604:Aflatoxin B1 / Q000032:analysis; D000348:Aflatoxins / Q000032:analysis*; D001966:Bromine; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D029745:Codonopsis / Q000737:chemistry; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*; D027861:Prunus / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D000348:Aflatoxins; D004365:Drugs, Chinese Herbal; C027955:aflatoxin G1; D016604:Aflatoxin B1; D001966:Bromine