evidence: Unfortunately, in January 2013, Dicyandiamide (DCD) was reported in New Zealand's Milk, and later found that it has been accumulated in milk through the food chain. Dairy farmers widely use DCD to promote the growth of grass. It also reduces the adverse effects of greenhouse gas emissions and nitrate leaching into waterways. It is also used to make pharmaceuticals, drilling mud for oil wells, dyestuffs, fertilizers, and explosives. However, the contamination of DCD in high concentrations in food products was reported to be toxic to humans(Lin et al., 2015). As a result, the New Zealand government banned the sale of milk products containing DCD. [...] DCD, or Cyanoguanidine, is a guanidine with a cyano group replacing one of its amino hydrogens, exhibiting two tautomeric structures, as shown in Figure 1. The form of protonation and the nitrogen bonding to which the nitrile group is attached vary between the two isomers(Yogesha et al., 2019). According to the molecular structure, the nitrogen content of DCD is relatively highly similar to melamine. Hence, this could be easily used as a protein adulterant. Therefore, developing a reliable quantitative screening method for determining the concentration of DCD in Milk is essential.