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合成了新的杂环偶氮变色酸类试剂———２［２′（６甲氧基苯并噻唑）偶氮］１，８二羟基萘３，６二磺酸，并系统探讨了在ｐＨ４．５的邻苯二甲酸氢钾ＮａＯＨ介质中显色试剂与钛的显色反应特性。结果表明，在溴化十六烷基吡啶存在下，试剂与Ｔｉ（Ⅳ）形成２∶１的络合物，显色反应１５ｍｉｎ完全并至少稳定４ｈ，最大吸收波长为６７０ｎｍ，表观摩尔吸光系数达１．６７×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，钛的质量浓度在０～４００μｇ／Ｌ时符合比尔定律。用拟定的方法测定了硅砖等标准物质中的Ｔｉ（Ⅳ），所得结果与标准值的相对误差均小于４％，ＲＳＤ（ｎ＝５）小于３．５％。
Synthesis of a new heterocyclic azo chromotropic acid reagents --- 2 2 (6 methoxy benzothiazole azo] 1, 8 dihydroxy naphthalene 3,6 two Sulfonic acid. The color reaction of chromogenic reagent with titanium in pH4.5 potassium hydrogen phthalate-NaOH solution was systematically investigated. The results showed that the reagent formed a 2: 1 complex with Ti (Ⅳ) in the presence of cetylpyridinium bromide. The color reaction was complete and stable for at least 4 hours with a maximum absorption wavelength of 670 nm. The apparent molar absorptivity Up to 1.67 × 105L · mol-1 · cm-1. The Beer’s law is obeyed when the mass concentration of titanium is between 0 and 400 μg / L. The proposed method was applied to the determination of Ti (Ⅳ) in standard materials such as silica bricks. The relative errors between the results and the standard values were less than 4% and RSD (n = 5) was less than 3.5%.