This test paper allows the quick and easy detection of hydrocyanic acid and cyanides in aqueous solutions and extracts. They are for example formed in the manufacture of fruit brandies and are toxic even in low concentrations.

• Colour change: Pale-green to blue

To detect cyanides in solution, a drop of concentrated sulphuric acid is added to 10 ml sample. Hydrocyanic acid gas is formed and can be detected at the boundary layer between water and air.

Limit of sensitivity: 0,2 mg/L hydrocyanic acid (HCN)