应用等色染料离子对的褪色反应测定中草药中硒(Ⅳ)的含量

Determination of amounts of selenium(Ⅳ) in Chinese herbal drugs using the decolorant reaction of isochromatic dye ion-pair

目的:建立测定中草药中硒的一种新的催化动力学光度法。方法:在酸性介质中,硒(Ⅳ)能催化H2O2氧化溴酚蓝-丁基罗丹明B的褪色反应,硒(Ⅳ)含量在0～5μg/L范围内与褪色反应速率成正比。结果:样品经HNO3-HClO4消化后直接测定硒(Ⅳ)的含量,该方法具有良好的选择性和准确度。结论:该法可用于中药材中硒的测定,结果令人满意。

Objective： To describe a new spectrophotometric method for the determination of selenium （Ⅳ） in Chinese herbal drugs. Methods： The selenium（Ⅳ） catalyzed oxidation of bromophenol blue-butylrhodamine B with H202 in nitric acid medium. And as the redox reaction proceeds, the purple color was decolorized. The decolorant reaction showed a good linear relationship with the amounts of selenlum（Ⅳ）. The detection range of the method was 0-5 μg/L.Results：Samples after digesting of HNO3-HClO4 determined the amounts of selenium （Ⅳ）. The method was selectivity and precise. Conclusion： It is applied to the determination of selenium in Chinese herbal drugs and with satisfactory results.