Comparison of Dumas Combustion Method and Kjeldahl Nitrogen Determination Method in Determination of Total Nitrogen in Fertilizer
To evaluate the applicability of Dumas combustion method and Kjeldahl nitrogen determination method in determining the total nitrogen content of different types of fertilizers,20 different types of nitrogen-containing fertilizers and 4 standard samples were selected as experimental objects.Dumas combustion method and Kjeldahl nitrogen determination method were used to determine the total nitrogen content,and the precision,accuracy,correlation of the results,and advantages and disadvantages of the two methods were compared.The results showed that there was no significant difference between the two methods in determining fertilizers without nitrate nitrogen,but the precision of Dumas combustion method was higher.When measuring nitrate nitrogen-containing fertilizers,there was a significant difference in the results of the two methods.The results of Dumas combustion method were closer to the true content and had good repeatability,while Kjeldahl nitrogen determination method had a lower value and poor repeatability.For urea nitrogen fertilizers with high nitrogen content,the precision of Kjeldahl nitrogen determination method was slightly higher than that of Dumas combustion method.Taking into account factors such as environmental friendliness,work efficiency,experimental costs,precision and accuracy of the measurement results,Dumas combustion method is more suitable for determining the total nitrogen content of fertilizers.