钒(Ⅴ)-5-Br-PADAP-H_2O_2-吐温-80显色体系的研究与应用

Spectrophotometric Determination of Vanadium with 2-(5-Bromo-2-Pyridyl-Azo)-5-Diethyl-Aminophenol and Hydrogen Peroxide

研究了在非离子表面活性剂吐温 - 80存在下 ,钒 ( )与 2 - [(5 -溴 - 2 -吡啶 ) -偶氮 ]- 5 -二乙氨基苯酚 (5 -Br- PADAP)及 H2 O2 的显色反应。实验表明 :在 p H1.5— 4 .0范围内 ,钒 ( )与 5 - Br- PADAP、H2 O2 形成稳定的配合物 ,最大吸收峰位于 5 95 nm处 ,表观摩尔吸光系数为 6 .2× 10 4L· mol-1· cm-1,配合物组成比为钒 ( )∶ 5 - Br- PADAP∶ H2 O2 =1∶ 1∶ 1。钒含量在 0— 15μg/ 2 5 m L范围内服从比耳定律。该方法灵敏度较高 ,用于合成水样中钒的测定 ,结果令人满意。

Colour reaction of vanadium(Ⅴ) with 2 (5 bromo 2 pyridyl azo) 5 diethyl aminophenol and hydrogen peroxide was studied. At pH 1.5-4.0 a stable 1∶1∶1 chelate was formed in aqueous solution in the presence of polysorlatum 80. The apparent molar absorptivity is 6.2×10 4L·mol -1 ·cm -1 at 595nm. Beer's law is obeyed in the range of 0-15μg/25mL for vanadium .The proposed method has been applied to the determination of vanadium synthetic water sample with satisfactory results.