GB/T 24101-2018 "Limit and Determination of 4-Aminoazobenzene in Dye Products" is applicable to various types of dye products. It specifies the limit requirements and determination methods for 4-aminoazobenzene. After extraction and reductive decomposition, the sample is preliminarily qualified using thin-layer chromatography, followed by quantitative analysis using gas chromatography-mass spectrometry or high-performance liquid chromatography. The standard defines the limit indicators for this substance, specifies the sample pretreatment process, chromatographic conditions, and criteria for result determination. The difference between two parallel determination results must meet precision requirements, providing a technical basis for controlling this harmful substance in dye products.