目的 :建立间接铈量法测定昆布中碘含量的方法。方法 :在弱酸性条件下 ,用定量的 Ce( SO4 ) 2 将 I- 氧化为 I2 并萃取在四氯化碳中 ,过量的 Ce4 +以邻二氮菲 - Fe( )为指示剂 ,用硫酸亚铁铵滴定液回滴的方法间接进行测定。结果 :测定线性范围2～ 10 mg( r=0 .9999) ,滴定误差± 0 .4 % ( n=5 ) ,平均加样回收率 99.4 % ( n=5 ) ,样品测定精密度 RSD=0 .7% ( n=5 )。结论 :结果准确可靠 ,方法简便易行。 Objective: To establish a method for the indirect determination of iodine in kelp by the cerium content method. Methods: I - was oxidized to I2 by quantitative Ce (SO4) 2 and extracted into carbon tetrachloride under mildly acidic conditions. Excess Ce4 + was treated with o-phenanthroline-Fe Ferrous ammonium titration solution back to the indirect method of determination. Results: The linear range was 2 ~ 10 mg (r = 0.9999), the titration error was ± 0.4% (n = 5) and the average recovery was 99.4% (n = 5) .7% (n = 5). Conclusion: The results are accurate and reliable, the method is simple and easy.