苯芴酮-溴化十六烷基三甲基铵分光光度法测定钛铁中锡

试样用硝酸、氢氟酸、硫酸溶解，以强碱分离法沉淀大部分干扰离子，以2.0 mL 150 g/L抗坏血酸溶液、1.0 mL 10 g/L草酸溶液掩蔽Al³⁺、Mn²⁺、Ti⁴⁺、V(Ⅴ)、Cl^-、F^-等干扰离子。在约0.9 mol/L硫酸介质中锡与苯芴酮、溴化十六烷基三甲基铵(CTMAB)作用形成三元络合物，并在536 nm处有最大吸光度，据此可实现锡的分光光度法测定。锡在0.1 ~1.0 μg/mL范围内符合比尔定律，线性相关系数为0.999 8。方法测定下限为0.030%。对钛铁试样中锡进行测定，结果与电感耦合等离子体原子发射光谱(ICP-AES)法的测定值相吻合，相对标准偏差(RSD， n=8)小于3.0%。

Determination of tin in ferrotitanium by phenylfluorone-cetyl trimethyl ammonium bromide spectrophotometry

The sample was dissolved with nitric acid, hydrofluoric acid and sulfuric acid. Most interference ions were precipitated by strong alkali separation. The interference ions of Al³⁺, Mn²⁺, Ti⁴⁺, V(V), Cl^- and F^- were masked by 2.0 mL of 150 g/L ascorbic acid solution and 1.0 mL of 10 g/L oxalic acid solution. In 0.9 mol/L sulfuric acid medium, the tin ions could react with phenylfluorone and cetyl trimethyl ammonium bromide (CTMAB) to form ternary complexes, which had maximum absorbance at 536 nm. Based on this, the spectrophotometric determination of tin was realized. Beer's law was obeyed for tin in range of 0.1-1.0 μg/mL. The linear correlation coefficient was 0.999 8. The low limit of determination of method was 0.030%. The content of tin in ferrotitanium sample was determined, and the found results were consistent with those obtained by ICP-AES. The relative standard deviation (RSD, n=8) was less than 3.0%.