Sintesis hapten asam 4-(4,6-diamino-1,3,5-triazin-2-ylamino) butanoat dan produksi antibodi untuk pengembangan deteksi selektif melamin menggunakan metode AGPT dan Elisa = Synthesis of hapten 4-(4,6-diamino-1,3,5-triazine-2-ylamino) butanoic acid and antibody production for the development detection selective of melamine used AGPT and Elisa method