title: A modified simple method for determination of serum α-tocopherol (vitamin E).
abstract: BACKGROUND
  Vitamin E is one of the important antioxidants linked to regulate various diseases, such as atherosclerosis, hypertension, and male infertility. A relatively simple and economic biochemical modified method has been developed to determine serum α-tocopherol concentration.
  
  
  METHODS
  The current modified method is based on previous Baker and Frank method and the method of Martinek by using 2,2'-bipyridyl, ferric chloride, and xylene. The complex of ferrous ions generated in this reaction with 2,2'-bipyridyl is determined by using a plain enzyme-linked immunosorbent assay microplate (non-antibody coated) at 492 nm.
  
  
  RESULTS
  The standard curve of this new modified method shows a linearity with correlation r=0.997 (concentration vs. absorbance). The absorbance of this color complex is directly proportional to the α-tocopherol concentration. The sensitivity of this new modified method has been compared and correlated with Baker and Frank method by using 15 human samples (r=0.99, p<0.0001).
  
  
  CONCLUSIONS
  This simple and economic method may be routinely used to analyze α-tocopherol concentration in serum.
authors.affiliation: Department of Physiology, Al-Ameen Medical College, Karnataka, India.
authors.forename: Jameel G
authors.initials: JG
authors.lastname: Jargar
authors.forename: Shaheenkousar H
authors.initials: SH
authors.lastname: Hattiwale
authors.forename: Swastika
authors.initials: S
authors.lastname: Das
authors.forename: Salim A
authors.initials: SA
authors.lastname: Dhundasi
authors.forename: Kusal K
authors.initials: KK
authors.lastname: Das
mesh_terms: D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000032:analysis*; D002138:Calibration; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards; D006801:Humans; D008875:Middle Aged; D012015:Reference Standards; D015203:Reproducibility of Results; D014810:Vitamin E / Q000097:blood*; D055815:Young Adult
chemical_list: D000975:Antioxidants; D014810:Vitamin E