ABSTRACT
AIM: We proposed a rapid and high quality method to determine α-tocopherol (α-T) in different biopharmaceutical samples using liquid chromatography-diode array detector on-line ESI-MS/MS. MATERIALS & METHODS: A working standard solution of α-T and internal standard, phenyl-5,7-dimethyl-d6-α-tocopherol, were used for optimization and validation of the method. Levels of α-T in nanoemulsions, serum and plasma samples were evaluated. RESULTS & CONCLUSION: Precision (1% for retention time, 5% for peak area and 3% for relative peak area), linearity range (among 0.625-20.0 µg ml-1), LOD and LOQ, accuracy and matrix effect were studied. The validated chromatographic method is presented as valuable analytical tool for the determination of α-tocopherol in loaded drug delivery systems and in biodistribution levels in blood samples.