【摘要】 研究了在阳离子表面活性剂溴化十六烷基三甲铵(CTMAB)存在下,9-(3,5-二溴)水杨基荧光酮(DBSAF)与镧(的显色反应及光度性能,建立了测定镧(的新方法。在pH 10.5NH3.H2O-NH4Cl缓冲溶液中,La(与DBSAF及CTMAB形成摩尔比为1∶2∶4的紫红色三元络合物,其最大吸收峰位于566.0 nm波长处,表观摩尔吸光系数为1.03×105L.mol-1.cm-1,在25 mL溶液中镧(量在0~24μg范围内符合比尔定律。该法已用于电子工业钛酸镧烧结中游离氧化镧的测定。更多还原

【Abstract】 In the presence of surfactant cetyltrimethyl ammonium bromide（CTMAB）,the photometric properties of color reaction of 93,5-dibromosalicyl fluorone（DBSAF）with La? were studied,and a new method was found for the determination of La?.The experimental results showed that La? reacted with DBSAF and CTMAB to form a micelle complex with a maximum absorption at 566.0 nm in a pH 10.5 NH₃·H₂O-NH₄Cl buffer solution.The apparent molar absorptivity of the complex,with a stoichiometric ratio of 1∶2∶4 is 1.03×10⁵ L·mol^-1·cm^-1.Beer’s law was obeyed in the range of 0～24 μg/25 mL for La?.The proposed method has been applied to the determination of trace La₂O₃ in the lanthanum titanate sinter with satisfactory results.更多还原