安培检测-离子色谱法测定乳品中的微量碘

 用安培检测 离子色谱法检测了乳品中的微量碘。以NaOH作淋洗液 ,直接进样 ,优化了碘的离子色谱分离和测定条件 ,方法的检测限达 1μg/L(3倍信噪比 )。测定了婴儿奶粉、孕产妇专用奶粉和鲜牛奶中的微量碘 ,加标回收率分别为 89 0 % ,86 0 %和 84 1%。

Determination of Micro Amounts of Iodide in Dairy Products by Ion Chromatography with Direct Amperometric Detector

A method was developed for the determination of micro amounts of iodide in dairy products by ion chromatography with direct amperometric detection. The eluent used was 0.04 mol/L NaOH. The relative standard deviations of retention times and peak heights for 1 mg/L and 2 micrograms/L iodide solutions were 0.67%, 3.9% (n = 8) and 0.97%, 1.8% (n = 8), respectively. Calibration curves showed good linearity with r = 0.9991 (n = 8, from 10 micrograms/L to 160 micrograms/L), and with r = 0.9986 (n = 8, from 400 micrograms/L to 5 mg/L). The detection limit of iodide by this method was 1 microgram/L. The method has been used to analyse two kinds of milk powder and a kind of fresh milk. The recoveries were 89.0%, 86.0% and 84.1% for infant formula milk powder, mother's milk powder and fresh milk, respectively.