5-Br-PNPFF与镍(Ⅱ)的显色反应及其分析应用

Studies on the Color Reaction of Nickel with 1-(5'-Rromo-2'-pyridyl)-5-(4'-nitrobenzophenons)-3-(2'-euran) Formazan and Its Application

研究了新试剂1-(5’-溴-2’-吡啶基)-5-(4’-硝基苯基)-3-(2’-呋喃基)甲■(5-Br-PNPFF)与镍(Ⅲ)的显色反应条件。在吐温-80存在下,pH5.0的邻苯二甲酸氢钾-氢氧化钠缓冲介质中,镍(Ⅲ)与5-Br-PNPFF形成1:2的深绿色配合物,其最大吸收峰在7 10nm处,ε_(710)=4.89×10~4 L/mol.cm^(-1)。选择性好,镍含量在0～300μg/L范围内符合比尔定律。用所拟方法测定钢铁中的微量镍,结果满意。

In this paper, the color reaction of nickel(Ⅱ) with newly synthesized 1-(5'-bromo-2'--pyridyl)-5-(4'-nitrobenzophenone)-3-(2'-furan) formazan (5-Br-PNPFF) has been studied. Inthe presence of nonionic surfactant Tween-80, the Ni-5-Br-PNPFF complex is formed in abuffer solution of pH 5.0. The apparent molar absorptivity of complex is 4.89×10~4L/mol. cm^(-1)at 710nm. Beer's law is obeyed in the concentration range of 0～300 μg/L. This method has beenapplied to the determination of microamounts nickle in the steel samples with satisfactory results.