What are the limitations of biuret test?

The biuret test has several limitations, including its inability to distinguish between different types of proteins or peptides, as it only detects the presence of peptide bonds. Additionally, the test can yield false positives in the presence of certain compounds, such as ammonium salts or some metal ions. It also requires a relatively high concentration of protein to produce a noticeable color change, which may limit its sensitivity for low-protein samples. Lastly, the biuret test is not suitable for detecting non-protein nitrogen compounds.