This standard specifies the test method for the determination of metal elements silver, gold, calcium, copper, iron, potassium and sodium in nitric acid by atomic absorption spectroscopy (AAS). It is suitable for the determination of trace metal elements in nitric acid used in the electronics industry. For the content of trace metal elements in nitric acid in the range of 0.1 mg/L to 1 mg/L, flame atomic absorption method (FL-AAS) should be used; for the content of elements in the range of 0.1 μg/L to 100 μg/L, the flame-free graphite furnace atomic absorption method (GF-AAS) should be used. When using this standard for the determination of nitric acid for the electronic industry, it should be ensured that the atomic absorption instrument is in an appropriate working environment. For samples with an element content below 100 μg/L, it is recommended to use a clean room not less than 100,000 class specified in GB 50472. This standard does not deal with safety issues in use, and the user should be responsible for establishing appropriate safety and health provisions and restrictions on the scope of use. The principle of the method is that after the sample is properly diluted, through the Flame atomization device or injection into the graphite furnace Atomizer, the ground state atoms of the metal element to be tested absorb the electromagnetic radiation of a specific wavelength radiated by the Light source. Absorption intensity is proportional to the concentration of the element to be measured in the sample, and is quantitatively determined by comparison with the standard series.