Cyanide is quantified by potentiometric titration, a method widely used in gold mining. It may also be based on titration with silver ion. KCN is used as a photographic fixer during the soaked plate collodion process.The KCN dissolves silver where it has not been made insoluble because of the developer. https://potassium-cyanide-for-sal31840.blogtov.com/10834294/details-fiction-and-potassium-iodide-pills-for-sale-walmart