The Iodine Starch test was developed in 1814. The test involves using iodine and an iodide (usually potassium iodide) in solution. It can detect extremely low levers of starch - the starch granules turning an intense dark blue-black colour.
It's a highly standardized test, and although in routine use for more than 200 years, the chemical mechanism of the reaction is still not known.
A 2016 research project suggested that the test might have similarities with a compound known as the pyrroloperyleneā€“iodine complex.
The crystal structure of the pyrroloperyleneā€“iodine complex (with a formula close to pyrroloperyleneā€“I2.2) has been solved. The structure contains infinite polyiodide chains, the Raman spectrum of which resembles that of the famous starchā€“iodine complex, thus casting light on a historical puzzle
Angewandte Chenie , Volume 55, Issue 28
Note: The test is also used in reverse, to detect low levels of iodine
Ideas for new topics, and suggested additions / corrections for older ones, are always welcome.
If you have skills or interests in a particular field, and have suggestions for Wikenigma, get in touch !
Or, if you'd like to become a regular contributor . . . request a login password. Registered users can edit the entire content of the site, and also create new pages.
( The 'Notes for contributors' section in the main menu has further information and guidelines etc.)
You are currently viewing an auto-translated version of Wikenigma
Please be aware that no automatic translation engines are 100% accurate, and so the auto-translated content will very probably feature errors and omissions.
Nevertheless, Wikenigma hopes that the translated content will help to attract a wider global audience.