This paper describes a new method for determination of trace amounts of cerium. The principle of the method as follows：Ce （IV） system which was absent of fluorescence became a characteristic fluorescence of Ce （Ⅲ） ion by adding ascorbic acid into Ce （IV） system,and re - adding a certain concentration formaldehyde solution, the new system had greater fluorescence intensity of the sensitizer. Thereby a new method of an indirect determination of trace cerium （IV） ion was established. With this method Cerium （IV） ion concentration in th...
