Monensin is an antibiotic used in animal feed to improve feed efficiency and prevent coccidiosis. However, the presence of impurities in the product can affect its safety and efficacy. Monensin impurities can be formed during the manufacturing process or due to storage conditions. These impurities may include monensin isomers or related compounds that can have toxic effects on animals or humans consuming the meat. Therefore, it is crucial to monitor and control the levels of monensin impurities in the product to ensure the safety and quality of animal feed.