溴代十六烷基吡啶增敏阻抑动力学光度法测定中草痕量镍——藏花红-KBrO_3指示体系

Inhibitory kinetic spectrophotometric determinationof trace nickel with cetyl pyridine bromide as sensitizet in Chinese herbal medicine

在稀硫酸介质中,增敏剂溴代十六烷基吡啶存在下,痕量Ni(Ⅱ)对溴酸钾氧化藏花红的褪色反应有显著阻抑作用,研究了其动力学条件。据此建立了溴代十六烷基吡啶增敏阻抑动力学光度法测定痕量Ni(Ⅱ)的新方法。方法线性范围为0～400μg/L,检出限为1.42×10-7g/L。本法在表面活性剂存在下,其灵敏度提高6倍。本法快速、灵敏、操作简便,用于草药中痕量镍的测定,结果良好。

An inhibitory kinetic spectrophotometric method was proposed for the determination of trace Ni（Ⅱ）. The method is based on the inhibition effect of Ni （Ⅱ） on catalyzed oxidation of Safranine T by potassium bromate in dilute sulphuric acid medium with cetyl pyridine bromide as Sensitizet and the kinetic conditions were studied. The linear range of the determination is 0-400 μg/L. The detection limit is 1.42×10^-7 g/Lo The sensitivityis increased by 6 times than in the absence of the surfactant. This method is simple, rapid and highly senstive. The method can be used for the determination of Ni（Ⅱ ） in Chinese herbal medicine with saisfactory result.