4-硝基-4′-氟苯基重氮氨基偶氮苯双波长分光光度法测定镍  

Determination of nickel by dual-wavelength spectrophotometry with 4-nitro-4′-fluorophenyl diazo-amino-azobenzene

作　　者：俞善辉[1] 冯卿[1] 吴斌才[2] 

机构地区：[1]华东理工大学化学与分子工程学院化学系,上海200237 [2]华东师范大学化学系,上海200062

出　　处：《冶金分析》2010年第1期61-64,共4页Metallurgical Analysis

摘　　要：报道了新含氟显色剂4-硝基-4＇-氟苯基重氮氨基偶氮苯与镍（Ⅱ）的显色反应。试验表明，在pH8．6Na：B4O7-HCl缓冲溶液、Twcen-85存在下，试剂与镍（Ⅱ）形成4：1的稳定紫红色络合物。最大吸收正峰为504nm，负峰为424nm；且在25mL显色液中镍（Ⅱ）的量在0～4μg范围内符合比尔定律。在两最大正负吸收波长处分别进行单波长分光光度法测定，表观摩尔吸光系数分别为1．13×10^5，1．06×10^5L·mol^-1·cm^-1.再以424nm为参比波长、504nm为测量波长进行吸光度叠加的双波长光度法测定，表观摩尔吸光系数为2．17×10^5 L·mol^-1·cm^-1。加入混合掩蔽剂NaF-硫脲，可消除常见共存离子的干扰。本法可用于测定多元素混合标准溶液和不锈钢中的镍（Ⅱ），回收率为96％～98％，混合标准溶液的测定值与认定值相一致。The coloring reaction between a novel fluoride-bearing reagent （4-nitro-4＇-fluorophenyl diazo-amino-azobenzene） and nickel（n） was studied. The results showed that, in presence of Tween-85, this reagent could form purple red complex with nickel（H） in Na2B4O7-HCl buffer solution at pH 8.6. The positive and negative maximum absorption peaks were at 504 nm and 424 nm,respectively. Beer＇s law was obeyed for nickel in the range of 0-4μg/25 mL. The apparent molar absorptivity determined by single-wavelength spectrophotometry at positive and negative maximum absorption wavelengths were 1.13 × 10^5 and 1.06 3×10^5 L.mol^-1.cm^-1 , respectively. The dual-wavelength spectrophotometric determination was conducted with 424 nm as reference wavelength and 504 nm as measuring wavelength. The apparent molar absorptivity was 2.17 × 10s L.mol^-1.cm^-1. The interference of common coexisting ions could be eliminated by adding mixed masking agent NaF-thiourea. This method could be applied to the determination of nickel（Ⅱ） in multi-element mixed standard solution and stainless steel. The recovery was 96 %-98 %, and the determination results of mixed standard solution were consistent with the certified values.

关 键 词：镍(Ⅱ) 4-硝基-4’-氟苯基重氮氨基偶氮苯 双波长分光光度法 

分 类 号：O657.32[理学—分析化学]