The basis of the determination is antigen antibody reaction, where the antibodies of two toxins are simultaneously connected in the column. After extraction and filtration, the sample slowly passes through the immunoaffinity column, where the endotoxin in the column binds to the corresponding antibody. Then, the immunoaffinity column is washed to remove any other unrelated substances that have not been bound. Wash the toxin with 2% acetic acid methanol and inject it into the analytical instrument for detection.