5-(4-氨基)亚甲基若丹宁光度法测定铜的研究

Cuprum Determination by Photometry of 5-(p-aminobenzylidene)rhodanine

研究了新试剂 5 -(4 -氨基 )亚甲基若丹宁 (ABR)与铜的显色反应 ,在 pH为 4 5的HAc -NaAc缓冲介质中 ,Tween -80存在下 ,ABR与Cu(Ⅱ)生成 2∶1的稳定络合物 ,λmax=5 0 0nm ,ε =1 64× 10 4 mol·L- 1 ·cm- 1 .铜的含量在 0～ 5 0 μg/2 5mL内符合比耳定律 .方法用于烟草中微量铜的测定 。

A 2∶1 stable complex with λ max =500*!nm and ε=1 64×10 4*!mol·L -1 ·cm -1 is formed when 5-(p-aminobenzylidene)rhodanine (ABR) reacts with cuprum in pH=4 5 HAc-NaAc solution and Tween-80 Cuprum content within 0～50*!μg/25*!mL conforms to Beer's Law This methor can be used for the determination of micro amounts of cuprum in tobacco