This work reports the chemical synthesis of aflatoxin B₁ (AFB₁)-lysine based on procedures available in the literature, but using lysine without a protection group in the α-amine group. AFB₁-exo-8,9-epoxide was obtained by epoxidation of AFB₁ with chloroperoxybenzoic acid in dichloromethane and phosphate buffer. Purification and identification of the AFB₁-lysine were conducted by liquid chromatography (LC), and its structure was confirmed by LC with mass spectrometer and diode-array detection. The preparation of AFB₁-lysine using lysine without a protection group in the α-amine group was completed in 24 h, being a practical modification of available methods that can be reproduced in analytical laboratories.