HG/T 5661-2019 "Determination of phthalene phenol in Spinning & weaving dyeing and finishing aids products" specifies the method for the determination of phthalene phenol (OPP) content in Spinning & weaving dyeing and finishing aids products using gas chromatograph-Mass spectrometry (GC-MS). This standard is suitable for evaluating the content of OPP in Spinning & weaving dyeing and finishing aids products. The process of solvent extraction, filtrate and GC-MS quantitative analysis can accurately determine the target ingredients in the product. This method can provide a reliable basis for product mass monitoring and compliance assessment to ensure that the product meets technical requirements and market standards.