Kjeldahl nitrogen analyzer is widely used to analyze the nitrogen content or protein content of food, crops, seeds, soil, fertilizer and other samples. Due to its wide range of applications, it is particularly necessary for operators to be proficient in its use.

When using Kjeldahl apparatus to determine the nitrogen content or protein content in a sample, the first operation to be performed is to measure the blank value. Although based on the principle of Kjeldahl nitrogen determination, theoretically the blank value has no influence on the measurement results, because the content in the sample is the final amount minus the blank value. However, in the actual analysis process, any measurement has errors. The error of titration volume of the blank and the titration volume of the sample are substituted into the calculation formula, if the titration volume of the blank is larger, then the blank error will be larger, and the calculated result will also be larger. Therefore, controlling the size of the blank titration volume can help improve the accuracy of analytical results.

The size of the blank titration volume has a certain impact on the measurement results of the Kjeldahl analyzer. Therefore, in the process of using the Kjeldahl analyzer for measurement, in addition to operating in accordance with the specifications, special attention should be paid to the blank value.