This International Standard specifies a high-performance liquid chromatographic (HPLC) method for the determination of the furazolidone content of premixtures and animal feeding stuffs. The method is applicable to animal feeding stuffs with a furazolidone content of 25 mg/kg to 5 000 mg/kg and to premixtures with a mass fraction of furazolidone of up to 20 % [formerly written as 20 % (m/m)]. NOTE 1 For animal feeding stuffs, the furazolidone content is expressed in milligrams per kilogram; for premixtures, as a mass fraction in percent [% (m/m)]. NOTE 2 Furazolidone is a chemotherapeuticum belonging to the group of nitrofuranes. Nitrofuranes are bacteriostatic or bactericidal against Gram-positive and Gram-negative microorganisms and against some moulds and protozoa.