I tried the standardization via the united states pharm (USP) compendium method which is vague. The method I used was found under the USP monograph stannous fluoride. At the moment I having difficultly with the color at the end point. As soon as I added less than 1ml of 0.1N potassium iodine-iodate the 50ml of standard 1000ppm Sn in HCl liberated the iodine and the starch indication turned dark blue?
I would greatly appreciate it if anyone had any links to methods or ideas.
Thanks
taylor