摘要
研究了 2 ( 5 硝基 2 吡啶偶氮 ) 5 二甲氨基苯胺 ( 5 NO2 PADMA)与铜的显色反应 ,建立了双波长分光光度法测定铜的新方法。结果表明 ,在pH 4.5HAc -NaAc缓冲溶液和乙醇存在下 ,Cu与 5 NO2 PADMA生成 1∶2的紫红色络合物 ,最大吸收正峰为 5 5 0nm ,负峰为 45 0nm ,正负峰吸光度绝对值之和与Cu浓度线性相关 ,Cu含量在 0～ 1.0mg/L内符合比尔定律 ,ε550 ,4 50 =6.74× 10 4 ,ε550 =3 .2 4× 10 4 。方法用于矿样中铜的测定 。
A new dual-wavelength spectrophotometric method for the determination of copper with 2-(5-nitro-2-pyridylazo)-5-dimethylaminoaniline (abb. as 5-NO_2-PADMA) has been developed.Copper reacts with 5-NO_2-PADMA to form a stable complex in a HAc-NaAc buffer solution at pH 4.5,the ratio of n_(Cu*')∶n_(5-NO_2-PADMA) in the complex is found to be 1∶2,the measuring and reference wave-lengths are 550 nm and 450 nm respectively.The apparent molar absorptivity is 6.74×10~4 L· mol^(-1)·cm^(-1),which is 1.1 times higher than that determined by single-wavelength spectrophotometric method. Beer's law is obeyed in the range of 0～1.0 mg/L for Cu.The method has been applied to the determination of copper in ores.
出处
《冶金分析》
CAS
CSCD
北大核心
2004年第6期16-18,共3页
Metallurgical Analysis
