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Other names 2-imidodicarbonic diamide, carbamylurea, imidodicarbonic diamide, allophanamide
CAS number 108-19-0
Molecular formula C2H5N3O2
Molar mass 103.080 g/mol
Melting point

186–189 °C (decomposes)

Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Biuret is a condensation compound of urea, equivalent to two molecules of urea less one of ammonia. It is a white solid soluble in hot water and decomposes at 186–189 °C. The parent compound can be prepared by heating urea above the melting point at which temperature ammonia is expelled.

2 CO(NH2)2 → H2N-CO-NH-CO-NH2 + NH3

A biuret is also a functional group and a class of organic compounds with the general structure RHN-CO-NR-CO-NHR where R is an organic residue. Biurets can be prepared by trimerization of isocyanates. For example the trimer of 1,6-hexamethylene diisocyanate is also known as HDI-biuret.

The biuret reagent is used in the biuret protein assay, a chemical test for proteins not because the reagent contains biuret but because both biuret and proteins have the same response to copper. However, the biuret test will also return a positive result in contact with polypeptides as it detects the peptide bonds.

The liquid form of Biuret is usually blue but turns violet when it comes in contact with protein or a substance with peptide bonds.

See also

Related compounds:


    This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Biuret". A list of authors is available in Wikipedia.
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