This European Standard is applicable to the quantitative analysis of (bound and free) hydrocyanic acid (HCN) in feed materials of plant origin and compound feed by High Performance Liquid Chromatography (HPLC). The method is validated from 10 mg HCN/kg to 350 mg HCN/kg. When the method is used outside this range it should be validated at least within the laboratory. A limit of quantification of 2 mg HCN/kg should normally be obtained.