Optimal analytical condition was obtained are that:the sample was extracted with water,then added sulfuric acid solution,potassium iodide solution,and four drops of ammonium molybdate.

• 结果表明,最佳分析条件为样品用水萃取后,依次加入硫酸溶液、碘化钾溶液、4滴钼酸铵溶液,用硫代硫酸钠标准溶液滴至近终点。