研究了不同条件下苯并三氮唑的紫外吸收光谱,最大吸收峰为273nm,常温下吸收强度不受温室影响,浓度线性范围为0~2.2μg·mL^-1,检出限为0.02μg·mL^-1,摩尔吸光系数为5.41×10^4L·mol^-1·cm^-1;建立了苯并三氮唑缓蚀铜粉中含氧量的测定方法。鉴于缓蚀铜粉由金属铜、铜氧化物和苯并三氮唑保护膜组成,用盐酸-H2O2分解样品后,分别以EDTA配位滴定和紫外光谱法测定化学缓蚀铜粉中铜和苯并三氮唑含量,差减求出该铜粉含氧量。方法 经济,仪器简单,操作方便,标准偏差=1.7%,变异系数为7.6%。结合国家标准方法,通过电解铜粉在成膜前后含氧量分析比较,提出的方法测定结果令人满意。
A method for determining the oxygen content in anti-corrosion copper powder with benzotriazole inhibitor surface film was established and the ultraviolet spectra of benzotriazole under various conditions were studied. The maximum absorption was at ;λmax=273nm, and the temperature did not influence the absorption intensity at normal temperature. The linear range of concentration was 0 -2.2μg·mL^-1, the detection limit was 0. 02 μg·mL^-1, and the apparent molar absorptivity of benzotriazole was ε=5.41×10^4 L· mol^-1· cm^-1 at 273 nm. Because the anti corrosion copper powder consisted of copper metal, copper oxide and benzotriazole protecting film, the Cu and BTA contents of the powder were determined through EDTA titration and ultraviolet spectrophotometry, respectively, after the samples were decomposed with HCl and H2O2, and the oxygen content of the powder was calculated by differential method. The instruments are simple, the method is economical, and the manipulation is convenient. The standard deviation is 1.7 %, and the differentiation coefficient is 7.6%. In conjunction with the application of the national standard method, the oxygen contents before and after the formation of the protecting film of the electrolyte copper powder were comparatively analyzed with satisfactory results.