A quantitative Biuret test for protein can be achieved by measuring the intensity of the color change produced when proteins react with the Biuret reagent, typically involving spectrophotometry for accurate results. Titration is not commonly used in this context, as the test primarily relies on colorimetric analysis. The brown result may occur if the sample contains high concentrations of certain substances or if the Biuret reagent is improperly prepared. For accurate quantification, standard curves using known protein concentrations are essential. This method provides a reliable way to assess protein levels in various samples.