Selenium in hormone medicines was oxidized to form Se( VI). Cd Se quantum dots with excellent fluorescence properties were synthesized using Se( VI) as a selenium source,Cd Cl2 as a cadmium source and hydrazine hydrate as a reducing agent in alkaline aqueous solution,refluxing in water bath. A new method for the determination of trace selenium was developed based on the linear dependency between the concentration of selenium and the fluorescence intensity of Cd Se quantum dots. The influence factors includi...