Differential pulse polarographic determination of total iodine in milk

A differential pulse polarographic method for total iodine in milk is presented. Samples are ashed, sodium hypochlorite is added to oxidize iodide to iodate, and the product is mixed with sodium sulfite solution and measured by differential pulse polarography at -90 V against SCE. The standard deviation for 53 duplicate samples was 0.011. Average recovery for 10 or more samples at different levels was 98.6% with a standard deviation of 2.9%.