Bismuth Subnitrate for Dragendorff's Reagent

[cafcom...@gmail.com]

I've been wanting to make Dragendorff's Reagent using Bismuth Subnitrate, but I can't find any sellers.  Is there a way I can synthesize this using Bismuth Nitrate(which I can get)?

[The Home Scientist]

That will work fine. Just about any bismuth salt works. In fact, I once made up a perfectly functional (if ugly) solution of Dragendorff's using technical grade hydrochloric acid from the hardware store and Pepto Bismol tablets. It wasn't the pure golden transparent solution that you get using reagent grade chemicals like those in the kit, but it worked just fine and was just as sensitive as the pure reagent. In fact, Dragendorff himself published several different formulations, and I suspect he just used whatever bismuth salt and acid he had on hand. The active species is a bismuth-iodide complex. However you produce it, it works.