The basis of the determination is antigen antibody reaction, where the antibodies of the three toxins are simultaneously connected to the column. After extraction and filtration, the sample slowly passes through the immunoaffinity column, where the three toxins bind to the corresponding antibodies. Then, the immunoaffinity column is washed to remove any other unrelated substances that have not been bound. Wash three types of toxins with eluent, and inject them into the analytical instrument for detection after nitrogen blowing and re dissolving.