In a blog post discussing the problem of iodine excess, some netizens posted a post that "iodine is volatile, you can’t buy iodized salt, you can put the iodized salt for a while and then eat it." There are also "fry the iodized salt in a pan, heat to volatilize iodine", "put salt early when cooking, stew to volatile iodine", these methods can really volatilize the iodine in the iodized salt

　　 The answer is: No! Because the iodine used in the production of iodized salt is "potassium iodate" (KIO3), not potassium iodide (KI) used in the past (before the 1990s). Potassium iodide is indeed not stable enough, easily volatile, destroyed or lost, but potassium iodate is relatively stable and not easy to destroy ("Chinese Journal of Endemic Disease Control" 1991, Vol. 6, No. 6).

　　According to the test ("Guangdong Trace Element Science" 1999, Vol. 6, No. 7), it is said that 10 grams of iodized salt is placed in 250 Add 200 ml of distilled water to the milliliter iodine measuring flask and dissolve it. After heating to boil for 30 minutes, determine the iodine content. As a result, iodine lost only 1.7%; after heating to 1 hour, iodine lost only 2%. This shows that long-term stewing has little damage to the iodine in the iodized salt. When the dissolved iodized salt is heated to 100 degrees and maintained for 10 minutes, only 1.2% of iodine is lost; when heated to 300 degrees (the temperature of ordinary frying is generally 180 degrees) for 10 minutes, only 5.2% of iodine is lost. It can be seen that high-temperature cooking has little damage to iodine in iodized salt. Another report (Volume 6 of the Endemic Disease Bulletin) pointed out that sunlight exposure has little effect on potassium iodate salt, even if the exposure is 128 hours, the iodine loss is less than 5%.

　　 I particularly admire the speed of knowledge update by some experts: 20 years unchanged, holding the old emperor''s calendar!