Determination of alpha-tocopherol in buccal mucosal cells using an electrochemical detector

Using HPLC with an electrochemical detector, tocopherol concentration in human buccal mucosal cells was determined, and compared with that in plasma, RBCs, and platelets. The values were expressed on the basis of protein concentration. The reproducibility and recovery were enough to be used clinically. In healthy young male adults, tocopherol concentration in buccal cells was 46.4 ng/mg protein, and this increased three fold, after daily administration of 600 mg of d-alpha-tocopherol for one month. Comparison of correlations between all the measurements showed that the highest correlations were between RBC tocopherol level and the tocopherol/lipid ratio in plasma, and between platelet tocopherol level and the tocopherol/lipid ratio. Tocopherol concentration in buccal cells correlated at r = 0.66 (p less than 0.03) with RBC tocopherol, r = 0.65 (p less than 0.03) with the tocopherol/lipid ratio, and r = 0.60 with platelet tocopherol concentration, respectively.