GB/T 45514-2025 "Spinning & weaving products, quantitative chemical analysis, mixture of polyarylate fibers and some Miscellaneous fibers" is a new detection standard for the Spinning & weaving industry in our country. The standard establishes a quantitative analysis technology system based on selective dissolving method for the mixture of high-performance polyarylate fibers, protein fibers, regenerated cellulose fibers and other 17 types of fibers. By standardizing the key links such as sample pretreatment, solvent selection (such as sulfuric acid solution at a specific concentration), and dissolving condition control, the content of each component in the mixture can be accurately determined. The standard is formulated by the National Spinning & weaving Standardization Technical Committee and the Fujian Fiber Inspection Center, which provides technical support for the quality control of special Spinning & weaving products in the fields of aerospace and protective equipment.