邻羧基苯基重氮氨基偶氮苯光度法测定热镀锌合金中微量镍

Spectrophotometric determination of micro nickel in hot-dipping zinc alloys with o-carboxyl-phenyl diazoamino azobenzene

拟定了一种高灵敏度、高选择性的分光光度法测定锌合金中微量镍。在pH10硼酸缓冲溶液中,表面活性剂(TritonX 100)存在下,镍与邻羧基苯基重氮氨基偶氮苯(简称o CDAA)形成砖红色络合物,其最大吸收波长为542nm,表观摩尔吸光系数ε可达到1 24×105。在25mL溶液中,镍量在0～6μg间呈线性关系,测定5μg镍时RSD为1 0%。该法灵敏、简单、稳定、快速,已用于热镀锌合金或锌中间合金中微量镍的测定,结果满意。

A high sensitive and selective spectrophotometric method for the determination of trace nickel in zinc alloy has been developed. In the boric acid buffer solution (pH = 10), nickel with a new chromogenic reagent o-carboxyl-phenyl diazoamino azobenzene forms a brick red stable complex which shows maximum absorption wavelength at 542 nm with a molar absorptivity of 1.24 × 105 L·mol-1·cm-1. Beer's law is obeyed in the range of 0 - 6 μg/25 mL for nickel. RSD is 1.0% for the determination of 5 μg/25 mL nickel. This method is very sensitive, simple, and it has been used for the determination of nickel in hot-dipping zinc alloy with satisfactory results.