Authors: Sara HABIF, Nevbahar TURGAN, Dilek ÖZMEN, 0ya BAYINDIR
Abstract: Peroxidation of membrane lipids is held responsible for tissue injury in several disease conditions. Vitamin E, which is localized in the membrane bilayer, protects subcellular membranes from the deleterious effects of endogenous and exogenous free radicals by breaking the chain of autooxidation in the process of lipid peroxidation. ln this study, vitamin E concentrations of 44 different serum samples were determined by a colorimetric method and high performance liquid chromatography (HPLC) and the results were compared. ln the colorimetric and in the HPLC method the lower detection limit of vitamin E was 0.1mg/dL and 0.02 mg/dL, respectively. Within-day precision (CV) was 5.70 and 1.87%, day-to-day precision was 7.20 and 1.62% and the analytical recovery was 84 and 97.5%, for the colorimetric and HPLC determinations, respectively. The difference between values obtained by two different methods was statistically insignificant (mean±SEM; 0.690 ± 0.313 using colorimetry; 0.679 ± 0.277 mg/dL using HPLC). The coefficient of correlation was significant (r=0.856; p<0.01). These findings suggest that, altough HPLC enables a rapid and accurate determination of vitamin E with relatively smoll sample volume, the calorimetric method, which is sufficiently accurate and economic, may be the appropriate choice in laboratory conditions where HPLC is not available.
Keywords: Vitamin E, colorimetry, HPLC