Discuss on Methods about Determining Crude Protein Content in Oil Cake

In this paper,kjeldahl method regulated by national standard?improved kjeldahl method and biuret method are used to measure the crude protein content in oil cake simultaneously.After comparing the results,we can draw a conclusion that the data acquired from improved kjeldahl method is bigger than kjeldahl method regulated by national standard and more approximate to the truth of crude protein content.On the other hand,the relative average deviation of the data gained from biuret method for a great amount of samples is bigger.However,biuret method has the advantages of simple operation and being effective,so it suited to be used as a quick measuring method in feed mill.