催化光度法测定煤矸石中痕量锡

Determination of Trace Tin in Coal Gangue by Catalytic Spectrophotometry

在浓度为 0 .0 5 mol/L的 H3PO4介质中 ,痕量锡对 Na H2 PO2 还原罗丹明B(Rh B)褪色反应有催化作用 ,褪色程度与 Sn含量线性相关 ,建立了催化吸光光度法测定痕量 Sn的方法。褪色反应随温度升高而加快 ,在沸水浴中 5 min,ΔA可达最大值 ,流水冷却后吸光度保持 12 h基本不变 ,溶液的最大吸收波长为 5 5 5 nm。方法检出限为 0 .0 35μg/L,吸光度变化与 Sn的质量浓度在 0～ 1.0μg/5 0 m L范围内符合比耳定律。本法已用于测定煤矸石中的微量 Sn。

Trace Sn catalyzes the decolorization reaction of rhodamine B (RhB) by NaH 2PO 2 in 0.05 mol/L H 3PO 4 solution and its catalytic extent is linear to the contents of Sn.Based on this,a catalytic spectrophotometric method for determining trace Sn was developed.The results show that the maximun absorption of the complex is at 555 nm,the detection limit is 0.035 μg/L for Sn and Beer's law is obeyed for Sn in the range of 0.0～1.0 μg/50 mL.The method was applied to the determination of trace Sn in coal gangue.