Ti（Ⅳ）－F~－－邻硝基苯基荧光酮－氯化十六烷基吡啶四元体系显色反应的研究

A Study on the Colour Reaction of Ti(Ⅳ)-F￣--o-Nitrophenylfluorone-Cetylpyridine Chloride

本文较详细研究了在Ｈ＿２ＳＯ＿４介质中，Ｔｉ（Ⅳ）－Ｆ￣－－ｏ－ＮＰＦ－ＣＰＣ体系水相光度法测定痕量钛的新方法。四元体系的最大吸收峰在５６５ｎｍ处，表观摩尔吸光系数为２．１×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），Ｓａｎｄｅｌｌ灵敏度为２．２８×１０￣（－４）μｇＴｉ／ｃｍ￣２。钛含量在０～４μｇ／２５ｍＬ范围内遵守比尔定律。方法用于土壤、粮食、牧草、蔬菜和中草药中钛的测定，结果满意。

A new spectrophotmetric method for the deter-mination of trace amounts of titanium has been devel-oped,based on the colour system of Ti(Ⅳ)-F￣--o-ni-trophenylfluorone(-o-NPF )-cetylpyridine chloride(CPC)in sulphuric acid medium. The maximum ab-sorption of the complex is at 565nm.The apparentmolar absorptivity is2.1×10￣5L·mol￣(-1)·cm￣(-1)at565nm.Sandell’s sensitivity is 2.28μg/cm￣2 Ti. Beer'slaw is obeyed for titanium from 0 to 4μg/25mL. Theproposed method has been applied to the determina-tion of trace amounts of titanium in soik, millet,herbs,vegetables and traditional Chinese herbalmedicines with satisfactory results.