【摘要】 基于pH 9．0的氨水-氯化铵缓冲溶液中,痕量铈(Ⅳ)对溴酸钾氧化溴甲酚紫褪色的指示反应有明显的催化作用。据此建立了痕量铈(IV)的光度测定法,铈量在0～4．0μg·L-1间与△A值间呈线性关系,检出限为0．092μg·L-1。用于测定人发、茶叶和大米样品中痕量铈(IV),结果的相对标准偏差在3．6％～5．4％之间,回收率在96％～103％之间。更多还原

【Abstract】 Remarkable catalytic effect on the oxidative decoloration reaction between potassium bromate and bromocresol purple by the presence of traces of Ce(IV) was observed in an ammoniacal buffer solution of pH 9. 0. Based on this fact, trace amounts of cerium(IV) were determined photometrically be measuring the difference in absorbance (AA) of the testing solutions in the presence and absence of Ce(IV) at the wavelength of 580 nm. Linear relationship between AA and concentration of Ce(IV) was found in the range from 0 to 4. 0μg of Ce(IV) per liter of solution, with a detection limit of 0. 092μg·L-1. In its application to the analysis of samples of human hair, tea and rice, RSD’s found were in the range of 3. 6% -5. 4%, and recoveries obtained were in the range of 96% -103%.更多还原