About 0.5 mL of the stock standard solutions of a-tocopherol and d-tocopherol was made up to 5 mL with ethanol with 0.025% BHT (w/v), and 0.1 mL of the stock standard solutions of ergocalciferol and cholecalciferol was made up to 50 mL with ethanol with 0.025% BHT (w/v). The stock solution of c-tocopherol was the same as the intermediate solution. We observed that the intermediate solutions were stable for 1 month at 4 C.