Chemical Forums

Specialty Chemistry Forums => Citizen Chemist => Topic started by: Okapi on December 17, 2014, 12:30:47 AM

Title: Extraction of Iodine from Table Salt?
Post by: Okapi on December 17, 2014, 12:30:47 AM: Hi everyone. This is my first post on the forum and I'm certainly no expert and have basically no experience with chemistry, but recently it became a growing interest of mine. I looked around my house for anything I could mess around with that wouldn't be potentially dangerous and found Iodized salt, which contains 45% iodine. My plan was to attempt to extract the iodine from this.
What I found on the internet was to first extract potassium iodide and then retrieve iodine from that, but I wondered if there was a simpler way, since Petroleum Ether seems kind of hard to find and I don't want to arouse law enforcement suspicions by buying weird chemicals.
I read that Iodine was soluable in Ethanol -- found in denatured alcohol from my garage. So I poured a bunch of salt into a Mason Jar, soaked it in Ethanol, poured it through a coffee filter into a ceramic bowl and then evaporated the Ethanol off. What I was left with was a very odd looking bubble formation of yellowish-white crystals and an extremely small trace amount of purplish pink on one edge of the bowl.
I'm guessing the purplish pink residue was Iodine, but I'm not 100% sure. As far as the yellowish white crystals, I don't know what that is. Would anyone be kind enough to enlighten me on whether or not my procedure would work for extraction of Iodine if I used a lot of salt?
Title: Re: Extraction of Iodine from Table Salt?
Post by: Hunter2 on December 17, 2014, 01:41:00 AM: All will not work, because iodine in table salt is added as sodium iodate NaIO₃ not as iodide. To extract this you need a litte chemical plant where precipitate the iodate or reduce it.
Title: Re: Extraction of Iodine from Table Salt?
Post by: curiouscat on December 17, 2014, 02:08:45 AM: Iodized salt contains 45% Iodine? That just sounds wrong to me.
Title: Re: Extraction of Iodine from Table Salt?
Post by: Zyklonb on December 17, 2014, 11:59:46 AM: From the Wikipedia page iodide seems to be around 15-45 mg/Kg of salt (presumably by the iodide ion mass, not sodium iodide).
I've tried to get iodine from salt before without success. However sea salt has worked for me in the past.
Also, iodate and iodide seem both be used, and I don't know how you could find out which is in your salt.
Title: Re: Extraction of Iodine from Table Salt?
Post by: Arkcon on December 17, 2014, 12:17:27 PM: Along those lines, you'd have better results using ashed seaweed, which bio-accumulate iodine.
Title: Re: Extraction of Iodine from Table Salt?
Post by: Zyklonb on December 18, 2014, 10:25:55 AM: Yeah, another good source is dead sea salt, which contains both iodide and bromide ions in concentrations far above regular ocean concentrations.