Iodized salt?

Molla A. Latif, Kapasia, Gazipur
How much iodine does the iodized salt contain? Last week, I had been to Rajshahi with some sea fish for my grand daughters because my son was complaining for long that they were running short of iodine there. When I asked him why didn't they take iodized salt? He counter questioned me, "Do you take that awful stuff?" Yes, I said. Then he got four packets of prominent brands of iodized salt and put lemon juice in the salt. As we knew the colour of the salt should turn pink, it did not turn so. I said that all these packets might not be of original brand or company. When I carried out the test getting the same brands from Dhaka market, they showed no iodine. I'm amazed or confused if the nature of iodine had changed or the prominent companies were not reliable.