Abstract:

An analytical method for determining iodine in food was developed using ion chromatography with amperometric detection. Before ion chromatographic separation, samples were suspended in potassium hydroxide solution with the presence of subsequently added sodium thiosulfate solution, vacuum dried and ashed. Some key sample pretreatment conditions were optimized. The limit of detection for iodine was 5μg/kg. The average spike recoveries of iodine in dried small shrimps and milk power were between 85.9% and 112.3%, and the determination precision varied from 1.26% to 4.54%. The results of determining four national standard reference materials, namely cabbage (GBW10014), spinach (GBW10015), milk powder (GBW10017) and chicken (GBW10018) by the developed method were consistent with the standard values.

Key words: ion chromatography with amperometric detection, food, iodine, ashing