GB/T 2910.9-2024 standard Part 9 specifies a method for quantitative chemical analysis of acetate fiber and Miscellaneous fiber mixtures by phenylmethanol method. This method is suitable for analyzing the proportion of acetate fiber and Miscellaneous fiber (such as cotton, polyester, etc.) mixed in Spinning & weaving products. The phenylmethanol method is based on the dissolving characteristics of acetate fibers in phenylmethanol solution. The content of acetate fibers in the mixture can be quantitatively analyzed by the determination of the dissolving process. The standard describes the operation steps, reagent preparation, experimental conditions and result calculation methods in detail to ensure the accuracy and repeatability of the analysis results. This standard provides an effective technical means for the Spinning & weaving industry to help manufacturers and inspection agencies to accurately determine the composition of Spinning & weaving products, especially in the quality control and product certification of acetate and Miscellaneous fiber blends.