This standard provides methods for the analysis of normal trace impurities and purity in benzene by Gas chromatography, CG and external calibrate, suitable for the detection of non-aromatic impurities and aromatic impurities. The standard applies to benzene with impurity concentrations ranging from 5 to 2000 mg/kg with detection limits including aromatic impurities of 0.9 mg/kg and 1,4-dioxane of 2.7 mg/kg. Standard values in SI units are required when using this method. Standard users should follow safety and health regulations and ensure compliance with relevant regulations.