Determination of bovine blood oleandrin by high-performance liquid chromatography and postcolumn derivatization

A high-performance liquid chromatographic procedure with a postcolumn fluorescence derivatization is developed for the analysis of oleandrin in bovine blood. Oleandrin is separated by an octadecylsilane-bonded column with a mobile phase containing dehydroascorbic acid. The effluent of the column is mixed with concentrated hydrochloric acid and passed through poly(tetrafluoroethylene) tubing maintained at 70 degrees C. The resultant fluorophores are detected at 465 nm with excitation at 348 nm. Simple solid-phase extraction using Sep-Pak tC2 is effective for sample purification. We found the minimal detectable quantity of oleandrin in plasma to be 1.5 ng/mL at a signal-to-noise ratio of 3:1.