This International Standard specifies a high-performance liquid chromatographic (HPLC) method for the determination of the iodide content of pasteurized whole milk and dried skimmed milk, when present at levels from 0,03 µg/g to 1 µg/g and 0,3 µg/g to 10,0 µg/g, respectively. NOTE 1 The method has been collaboratively studied with samples of liquid whole milk and dried skimmed milk. There are no reasons to expect that the method does not apply to skimmed or partially skimmed milk as well as to dried whole milk. NOTE 2 The method measures free (ionic) iodide. However, the total iodide content of fresh milk and good quality milk powder, in which no microbial growth has occurred, may contain a mass fraction of 5 % to 10 % of organically bound iodide. More iodide can be bound organically in milk where microbiological deterioration has occurred.