The GB/T 13371-1992 standard specifies a method for the determination of copper, iron, nickel, mg, manganese, zinc and silver in uranium dioxide powder and pellets by Atomic absirption spectropho-tometry, AAS. The standard covers the principle of the determination, the required reagents and materials, the Sample Handling step, the calculation of the analytical results, and the precision of the method. The method is suitable for the determination of trace amounts of copper, iron, nickel, mg, manganese, zinc and silver in uranium samples, and the determination range is 10~ 120 μg/g. After the sample is dissolved by nitric acid, it is extracted and separated with phosphoric acid tributyl ester, and elemental detection is carried out in an air-acetylene flame.