RhB褪色光度法测定煤矸石中微量铈

Spectrophotometric Determination of Trace Cerium in Coal Gangue by Decoloring Rhodamine B

研究了在H2 SO4 介质和聚乙烯醇 (PVA)的存在下铈 (Ⅳ )对紫红色罗丹明B(RhB)的褪色反应 ,褪色程度与铈 (Ⅳ )量线性相关 ,借此建立了测定微量铈 (Ⅳ )的分光光度法。结果表明在pH =1的H2 SO4 溶液中 ,有色溶液的最大吸收波长为 5 5 0nm ,方法检出限为 2 .5 μg·L- 1 。铈(Ⅳ )量在 0～ 2 .0 μg·ml- 1 范围内符合比耳定律 ,铈 (Ⅳ )的加标回收率在 98.7%～ 10 4.3 %之间。

The decolorization reaction of trace Ce(Ⅳ) with amaranth rhodamine B(RhB) in H 2SO 4 medium in the presence of polyvinyl alcohol(PAV) and the linear relationsship of fading level with Ce(Ⅳ) content were studied. Based on this study, a decolouring spectrophotometric method for determining trace Ce(Ⅳ) was developed.The results show that the maximun absorption wavelength of the color solution in H 2SO 4 solution with pH 1 is at 550 nm and the detection limits of the method is 2 5 μg·L -1 for Ce(Ⅳ). Beer′s law is obeyed for Ce(Ⅳ) in the range of 0～2 0 μg·ml -1 , and the standard recovery of Ce(Ⅳ) is 98.7%～104.3%. The method has been applied to the determination of trace Ce in coal gangue with satisfactory results.