流动注射浊度分析法测定茶叶中钾的研究

A Study on Trubidimetric Determination of Potassium in Tea by Flow Injection Analysis

在聚乙烯醇介质中,基于钾离子和四苯硼钠形成稳定的胶体沉淀,建立了流动注射浊度法测定钾的快速分析方法。钾离子浓度在0～25.0μg/ml范围内符合比耳定律,相关系数0.9985。采用微波溶样,测定茶叶中钾,回收率在94.6%～103.4%之间,相对标准偏差小于3%。比较火焰光度法测定,结果满意。

In the polyviny alcohol medium,a flow injection analysis on turbidimetric determination of potassium was studied.The method was based on the reaction of potassium with sodium tetraphenylboron(TPB) to form a stable colloidal precipitation.Beer’ s law was obeyed in the range 0? 25.0μ g/ml of potassium.The samples were digested by microwave.The recovery obtained by standard addition method was 94.6% ? 103.4% .The relative standard deviations obtained (n=8) was less than 3% .The frequency of analysis was 60 samples per hour.The proposed method was rapid,simple and convenient and it has been applied successfully to determine potassium in tea samples.