This GSO standard specifies two methods for the determination of the aflatoxin B1 content of animal feeding stuffs. 1.1 Method A is applicable to the following simple feeding stuffs: - Oilseeds, and oilseed residues, and in particular ground-nut, copra, linseeds, soya, sesame and babassu palm. - Manioc meal; - Maize germ expeller; - Cereals and cereal products; - Pea meal; - Potato pulp and flour. In the presence of substances interfering with the determination by method A, it is recommended that the determination be carried out in accordance with method B. 1.2 Method B is applicable to mixed feeding stuffs and to simple feeding stuffs not mentioned in 1.1. This method is not applicable to feeding stuffs containing citrus pulp. 1.3 The lower limit of detection of aflatoxin B1 is 0,01 mg/kg