The term "biuret" also describes a family of organic compounds with the chemical formula R1R2N−C(=O)−N(R3)−C(=O)−NR4R5, where R1, R2, R3, R4 and R5 are hydrogen, organyl or other groups.

After that, it can be recrystallized repeatedly from 2% sodium hydroxide solution and water to finally get base-free crystalline needles of the monohydrate which are free of cyanuric acid.

[3] In general, organic biurets (those with alkyl or aryl groups in place of one or more H atoms) are prepared by trimerization of isocyanates.

In the anhydrous form, the molecule is planar and unsymmetrical in the solid state owing to intramolecular hydrogen bonding.

It is based on the biuret reagent, a blue solution that turns violet upon contact with proteins, or any substance with peptide bonds.