微波消解—催化光度法测定茶叶中的硒

Microwave Digestion-Catalytic Photometric Method for Determination of Selenium in Tea

在硫酸介质中，硒（Ⅳ）能催化溴酸钾氧化碱蓝6B使之褪色。研究了这一催化反应的动力学条件，并对茶叶样品进行微波消解处理，建立了一种动力学光度法测定痕量Se（Ⅳ）的新方法。Se（Ⅳ）的含量在4×10^-5-4．8×10^-4μg·mL^-1。范围内与吸光度A呈良好的线性关系，相关系数R为0．9994，样品的回收率为98．9％。该方法测定茶叶中微量硒，所用仪器简单，简便快捷，选择性好，灵敏度高。

Trace selenium（IV） can catalyze the fading reaction of Alkali Blue 6B by potassium bromate oxidation in sulfuric acid medium. The condition of kinetics have been studied in detail, and the tea samples pretreatment process using microwave digestion and a new method of kinetic spoctrophotometry for the determination of trace selenium（IV） was established. At the content of sele- nium （IV） range in 4 × 10-5 - 4.8 × 10-4μg·mL^- 1, between content and A values showed a good linear relationship, the corre- lation coeflqeient is 0.9994. The average recovery of this method can reach about 98.9% . The method advantages such as simple apparatus, quick detection, high sensitivity and selectivity. Satisfactory results were obtained for the determination of trace selenium in tea.