茜素紫褪色光度法测定食盐中碘  

Photometric Determination of Iodine in Table Salt by Oxidation Decoloration of Alizarin Purple

作　　者：马占玲[1] 

机构地区：[1]渤海大学化学化工学院商检教研室,锦州121013

出　　处：《理化检验（化学分册）》2009年第7期803-804,共2页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

摘　　要：提出了加碘盐中碘含量测定的光度分析法,在约0.1 mol.L-1硫酸条件下碘酸根氧化茜素紫使其褪色;在茜素紫的吸收峰456 nm波长处测定时,其吸光度的降低程度(ΔA)与碘质量浓度在50.0 mg.L-1以内呈线性关系。方法的相对标准偏差小于1%,平均回收率为104.5%。Based on the color-fading of alizarin purple by oxidation with iodate in a H2SO4 solution of ca. 0. 1 mol ·L^-1 , a photometric method for determination of iodine in table salt was proposed. The magnitude of decrease in absorbance （△A） was found to keep linear relationship with concentration of iodine in the range within 50. 0 mg· L^-1 as measured at the absorption maximum of 456 nm. Test for recovery was made by standard addition method and value of average recovery obtained was 104. 5%. Precision was tested at 5 different concentration levels for 6 determinations, values of RSD＇s found were all less than 1%.

关 键 词：光度法 碘 褪色 茜素紫 食盐 

分 类 号：O657.31[理学—分析化学]