5-Br-PADAP分光光度法测定铁矿石中的锌

Determination of Zinc in Iron Ore with 5-Br-PADAP Spectrophotometry

研究了5-Br-PADAP分光光度法测定微量锌的显色条件问题。实验结果表明,在pH值为7.0~10.0的硼砂-盐酸缓冲溶液中,在表面活性剂OP-10存在的条件下,Zn2＋与5-Br-PADAP形成了配合比为1∶2（物质的量比）的红紫色配合物,其最大吸收波长λmax=552nm,锌的质量浓度在0~125μg/25mL时,服从比尔定律,表观摩尔吸光系数为1.2×105 L/（mol·cm）。用该方法测定铁矿石中的微量锌,灵敏度高,准确性好,操作简便,安全快速。

Color conditions of 5-Br-PADAP spectrophotometry in determining trace zinc were studied. The results indicated that purpureal complex was synthesized in the borax-hydrochloric acid buffer solution at pH 7.0 - 10.0 with surfactant OP-10. Zn^2＋ and 5-Br-PADAP in the complex is 1 ： 2 （molar ratio）. The maximum absorption wavelength is λmax=552 nm. The Beer＇s law is obeyed in mass concentration of 0-125 μg/25 mL for zinc. The apparent molar absorption coefficient is 1.2 × 10^5 L/（mol · cm）. The method has advantages of high sensitivity and veracity, simple operation, safety and rapid when applied to the determining trace zinc in iron ore.