三种不同方法测定砖茶中氟含量的比较

Study of three methodology comparison on determination of Brick-tea Fluoride

目的 研究砖茶氟含量的测定方法。方法 分别用砖茶氟卫生标准 (讨论意见稿 )中的粉碎沸水浴、食品中氟的测定方法粉碎盐酸浸泡、四川农大的全叶熬煮 3种不同方法对 10份砖茶样品进行离子选择电极法测定。结果 3种不同缓冲液对同一茶汤氟的检出没有差别 ,而不同前处理方法氟的浸出率差异较大 ,其中粉碎盐酸浸泡只占粉碎沸水浴的 49.5 %～ 61.0 % ,平均 5 5 .1% ,全叶熬煮占粉碎沸水浴的 62 .4%～ 80 .9% ,平均70 .6%。结论 3种不同的测定方法测定结果有较大差异 ,不同的缓冲液对测同一茶汤氟没有明显的差异 ,不同的前处理方法都只浸出了部分氟。砖茶氟测定方法 。

Objective To study the method of determination the brick tea fuoride.Methods Ten samples of brick tea were determined by the ISE,which was treated by the water boiling after being shattering (hygienic standard of brick tea fluoride) and by acid immersing (fluoride determination in food) and the water boiling un shattered,respectively.Results No significant difference was found in the fluoride of tea soup used by three different buffers.But being used different pre treated methods,the rate of the fluoride infusion was significant.The fluoride content of brick tea infusion treated by acid immersing accounted for 49.5~61.0% of that treated by water boiling being shattered.Mean was 55.1%.The fluoride content of brick tea treated by water boiling without being shattered accounted for 62.4%~80.9% of that treated being shattered.Mean was 70.6%.Conclusions There was significance among the three methods.Different buffers has no significance to the same tea soup.Only part of content of fluoride was infused by different pretreated all.The method of determination of the brick tea fluoride,especially the pre treated should be considered about the custom of the minority.