Optimization of Photometric Method for Iodine Determination in Foods

  • J. Rudolfova Department of Dairy and Fat Technology,
  • L. Curda Department of Dairy and Fat Technology,
  • R. Koplik Department of Food Chemistry and Analysis, Institute of Chemical Technology, Prague


Determination of trace amounts of iodine in food samples was performed by a spectrophotometric method based on the Sandell-Kolthoff reaction catalysed by iodide ions. Samples were decomposed by wet digestion using a HNO3-HClO4-H2SO4 mixture. The amounts of reagents as well as reaction temperature and time were optimised. The accuracy of the method was tested by examination of the iodine recovery and by analysis of a certified reference material. It was found by the analysis of variance that mineralization had a statistically more significant effect on the assay accuracy than the catalytic reaction itself.