This product adopts the principle of competitive inhibition immunoassay. After extraction from the sample, quinoxaline binds to the specific antibody labeled with colloidal gold, inhibiting the binding of the antibody to the antigen BSA conjugate on the detection line (T-line) in the detection card, resulting in a change in the color depth of the detection line. Qualitative determination of quinoxaline in the sample is made by comparing the color intensity of the detection line with the quality control line (C line).