Kjeldahl nitrogen analyzer is widely used in food processing, grain, feed, water, soil, pharmaceuticals, animal husbandry, soil fertilizer, environmental testing, medicine, pesticides, scientific research, teaching, quality supervision and other fields to determine nitrogen or protein content.

Using Kjeldahl apparatus to determine the nitrogen content of samples requires three steps: digestion of the sample, distillation, and titration to calculate the nitrogen content result. The reasons that affect the recovery rate are closely related to these three steps. The reasons are as follows:

1. During the digestion, the digestion temperature is too low or the time is insufficient, so the sample is not completely digested, or there is wall hanging phenomenon when digesting the sample.

2. The standard solution of hydrochloric acid or sulfuric acid is placed for too long, resulting in inaccurate solubility.

3. The condensation tube or splash-proof tube of the distillation device of the nitrogen analyzer is damaged, and the ammonia gas produced leaks.

4. The collection liquid is too little to immerse the outlet of the receiving tube.

5. The concentration of hydrochloric acid or sulfuric acid standard solution is too high, and the recovery rate is easy to be low during manual titration.

6. When the temperature of the collecting solution for ammonia gas exceeds a certain temperature, ammonia gas is easily escaped.

Kjeldahl analyzer has the characteristics of high sensitivity, fast analysis speed, wide application range, less sample required, and simple operation. When doing sample testing, it is necessary to strictly follow the operating procedures of Kjeldahl nitrogen analyzer, including the temperature setting during digestion, the ratio of catalysts, the digestion time, etc.