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 modifi ed method has been developed to determine serum α -tocopherol concentration. Methods: The current modifi ed 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 modifi ed 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 modifi ed 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.