新显色剂1-羟基-2-(5-NO_2-2-吡啶偶氮)-8-氨基-3,6-萘二磺酸与钯的显色反应

Study on colour reaction of palladium with 1-hydroxy-2-(5-nitro-2-pyridylazo)-8-aminonaphthalene-3,6-disulfonic acid

探讨了新显色剂 1 羟基 2 ( 5 NO2 2 吡啶偶氮 ) 8 氨基 3,6 萘二磺酸 (简称 5 NO2 PAH)与钯离子显色的适宜条件及其共存离子的影响 ,建立了 5 NO2 PAH测定钯的新显色反应体系。结果表明 ,在pH 2 .0～ 5 .5范围内 ,钯与试剂形成稳定的 1∶1配合物 ,其最大吸收峰位于 71 2nm ,表观摩尔吸光系数εPd=2 .84× 1 0 4 L·mol- 1 ·cm- 1 ,钯的浓度在 0～ 2 0 μg/1 0mL范围内遵守比尔定律。

The optimum condition for colour reaction of palladium with the new reagent 1 hydroxy 2 (5 nitro 2 pyridylazo) 8 aminonaphthalene 3,6 disulfonic acid (5 NO 2 PAH) was studied. The experimental results showed that, in the pH range of 2.0～5.5, palladium could react with 5 NO 2 PAH to form a stable complex exhibiting two absorption peaks at 712 and 757 nm respectively. The apparent molar absorptivity at 757 nm is 2.84×10 4 L·mol -1 ·cm -1 . Beer's law was obeyed in the range of 0～20 μg/10 mL of palladium. The method was applied to the determination of palladium in samples with satisfactory results.