| 摘要 |
PURPOSE:To determine the content of Sm in a red phosphor simply, by a method wherein a recovered phosphor treated by alkali to remove an Al film, and Sm, Y and Eu are quantitatively determined after the dissolution of the film in acid and the results are converted into oxides. CONSTITUTION:Recovered phosphor as a sample is treated in an NaOH solution to dissolve an Al film alone contained in the sample. The solution is filtered, the residue is dissolved by heat in nitrohydrochloric acid and Sm, Y and Eu as component of a red phosphor are determined, for example, by high frequency induction bond analysis. Sm, Y and Eu in the red phosphor exist as oxides -- Sm2O3, Y2O2S and Eu2O3 and hence, values thus determined are translated into oxides. The proportion of Sm2O3 in the total oxide corresponds to the content of Sm contained in the red phosphor. Thus, the content of Sm can be determined even when the weight of the red phosphor is unknown.
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