This standard specifies a method for the determination of copper content in lithium by flame atomic absorption spectroscopy (AAS), suitable for the determination of copper content between 0.0010% and 0.1%. Method Absorbance of copper is determined at 324.7 nm using an air-acetylene flame by dissolving the sample in a dilute muriatic acid medium. The standard describes in detail the preparation of reagents, Sample Handling and measurement procedures to ensure the accuracy and precision of measurement results, providing a scientific basis for the detection of copper content in lithium products.