共振光散射法测定食品中的碘  

Determination of Iodine in Food by Resonance Light Scattering Method

作　　者：李咏梅[1] 李人宇[2] 施鹏飞[1] 

机构地区：[1]淮海工学院化学工程学院,江苏连云港222005 [2]连云港师范高等专科学校化学化工系,江苏连云港222006

出　　处：《食品科学》2012年第8期151-154,共4页Food Science

基　　金：国家自然科学基金青年科学基金项目(21101069)

摘　　要：基于在0.03mol/L磷酸中,碘(Ⅴ)与过量的碘化钾和溴化十六烷基吡啶反应成1:1离子缔合物,可导致共振光散射明显增强的原理,建立共振光散射法测定痕量碘的新方法。考察酸度、试剂用量、反应温度和反应时间对测定的影响,确定最佳测定条件。结果表明:最大共振光散射峰波长为469nm;共振散射光强度增加值与碘(Ⅴ)质量浓度在0.02～0.4μg/mL范围内线性关系良好,方法的检出限为0.033μg/L。方法用于测定加精制海盐、紫菜和海带中碘,结果与碘量法一致,相对标准偏差为0.7%～1.2%(n=5),回收率为98.4%～101.5%。A new resonance light scattering（RLS） method for the determination of trace iodine was developed based on the principle of I（Ⅴ） reacting with excessive potassium iodide and cetylpyridimium bromide to form an ion-associated complex（1：1） in the presence of 0.03 mol/L H3PO4,thus resulting in an obvious enhancement of RLS.Reaction conditions including acidity,reagents dosage,reaction temperature and reaction time were optimized.An excellent linear relationship between the enhanced RLS intensity and I（Ⅴ） concentration was achieved in the range of 0.02-0.4 μg/mL with the maximum RLS peak wavelength at 469 nm.The detection limit was 0.033μg/L.The method was applied to the determination of iodine in refined sea salt,laver and kelp samples.The results were in good agreement with those obtained by iodimetry.The relative standard deviation was 0.7%-1.2%（n=5）,and the recovery rate was 98.4%-101.5%.

关 键 词：碘 共振光散射 碘化钾 溴化十六烷基吡啶 食品 

分 类 号：O657.3[理学—分析化学]