气相色谱法测定婴幼儿配方谷粉中的碘

建立婴幼儿配方谷粉中碘的气相色谱定量分析方法。样品经α-淀粉酶水解,利用乙酸锌和亚铁氰化钾作为沉淀剂将样品中的蛋白质除去,在硫酸环境中把碘离子氧化成碘,碘与丁酮反应生成3-碘代-2-丁酮,用正己烷萃取,气相色谱法定量检测。碘的含量在0.04~0.48μg/m L范围内与色谱峰面积呈现良好的线性关系,线性相关系数r=0.998 2,方法的检出限为90μg/kg。测定结果的相对标准偏差为3.49%(n=6),样品加标回收率为86.2%~95.6%。该方法具有较高灵敏度和准确度,适用于婴幼儿配方谷粉中碘含量的检测。

Determination of Iodine in Formula Foods for Infant and Young Children by Gas Chromatography

sA method for the determination of iodine in formula foods for infant and young children by gas chromatography was developed. The sample was hydrolyzed byα-amylase. The protein in the sample was removed by using zinc acetate and potassium ferrocyanide as the precipitating agent. The iodine ion was oxidized into free iodine with hydrogen peroxide under sulfuric acid environment,and free iodine reacted with 2-butanone to produce 3-iodine-2-butanone, which was exracted withn-hexane and determined by gas chromatography. The content of iodine had good relationship with the chromatographic peak area in the range of 0.04-0.48μg/mL,the linear correlation coefficientr was 0.998 2,and the detection limit was 90μg/kg. The relative standard deviation of determination results was 3.49%(n=6). The recoveries ranged from 86.2% to 95.6%. This method was suitable for determination iodine in formula foods for infant and young children with advantages of high sensitivity and accuracy.