摘要
研究了新合成显色剂2（5硝基4甲基2吡啶偶氮）5二甲氨基苯胺（5-NO2-4-CH3-PADMA）与钯（Ⅱ）的显色反应.结果表明,在0.6～2.4 mol/L H2SO4介质中,5-NO2-4-CH3-PADMA与钯（Ⅱ）形成1∶1的绿蓝色络合物,其最大吸收峰位于621 nm,表观摩尔吸光系数为6.05×10^4 L·mol^-1·cm^-1,钯的质量浓度在0～3.2 μg/mL符合比尔定律.由于显色反应直接在强酸性介质中进行,其他金属离子几乎不显色,因此钯的测定具有很高的选择性,常见金属离子及100倍量的铑、25倍量铂、20倍量的钌、10倍量的银、7.5倍量的锇和5倍量的铱等贵金属离子不干扰钯的测定.所拟定的测定方法简便,快速,应用于催化剂和矿样中微量钯的测定,结果满意.
The chromogenic reaction between a newly-synthetic reagent, 2-（5-nitro-4-methyl-2-pyridy- lazo）-5-dimethylaminoaniline （5-NO2-4-CH3-PADMA） and palladium （Ⅱ） was studied. In 0.6--2.4 mol/L H2SO4 medium, palladium （Ⅱ） reacted with 5-NO2-4-CH3-PADMA to form a green-blue com- plex （1 ： 1） whose the maximum absorption wavelength located at 621 nm. The apparent molar ab- sorptivity was 6.05 × 10^4 L · mol^-1 · cm^-1. Beer＇s law was obeyed in the range of 0-3.2 μg/mL for palladium. Because the chromogenic reaction was conducted in strong acidic medium where other met- al ions seldom developed color, the determination of palladium showed a high selectivity. Common metal ions as well as Rh（Ⅲ） in 100 times, Pt（IV） in 25 times, Ru（Ⅲ） in 20 times, Ag in 10 times, Os（Ⅲ） in 7.5 times , and Ir（Ⅲ） in 5 times did not interfere in the determination. This method was simple and rapid. It was used in the determination of micro palladium in catalyst and ores with satisfactory re- sults.
出处
《冶金分析》
CAS
CSCD
北大核心
2014年第8期50-53,共4页
Metallurgical Analysis
基金
西安市科技计划项目(CXY13015-5)
