GB/T 23742-2009 specifies the determination method of muriatic acid insoluble ash in feed. The standard details the sample collection and preparation process, specifies the required equipment, including glass instruments commonly used in laboratories, high temperature furnaces, etc. Detailed determination operations, such as muriatic acid treatment steps, control of burning conditions, etc., also specify the form of calculation and reporting of results. The content of muriatic acid insoluble ash can reflect the impurities in the feed and affect the quality of the feed. This standard provides a unified measurement standard for the feed industry, helping to control the feed mass and ensure the health of farmed animals.