Free Cyanide (SM 4500-CN E Method)

The SM 4500-CN E method, which includes a test method for the determination of free cyanide, has been developed within the scope of the National Environmental Methods Index (NEMI), which creates a database containing environmental methods, protocols, statistical and analytical methods and procedures, and develops standard methods.

In the SM 4500-CN test method, after distillation, cyanide is converted to hydrogen cyanide gas, which is distilled and absorbed in sodium hydroxide solution. Due to the catalytic decomposition of cyanide in the presence of cobalt at high temperature in a strong acid solution, cobalt cyanide or cyanide complexes of noble metals, such as gold, platinum and palladium, are not fully recovered. Distillation also decomposes some organic cyanide compounds. It also separates cyanide from other color-producing organic or inorganic pollutants. Subsequent analyzes are for the simple salt, sodium cyanide.

The absorption liquid is analyzed by a titrimetric, colorimetric or cyanide ion selective electrode procedure. Of these, colorimetric methods (eg the 4500-CN E method) are ideally suited for cyanide concentrations as low as 1 to 5 μg/L.

Briefly, it contains free cyanide, hydrogen cyanide and cyanide ion.

In the tests and analyzes carried out in our organization, which has a wide range of technological equipment, trained and experienced staff and applies the most modern methods, national and international standards and legal regulations in force are complied with. Free cyanide (SM 4500-CN E method) services are among the numerous tests carried out in this context.