Kjeldahl analyzer related questions and answers

Kjeldahl analyzer related questions and answers

Kay-type nitrogen analyzer can be divided into automatic K-type nitrogen determination instrument and semi-automatic nitrogen determination instrument. The automatic K-type nitrogen determination instrument includes digestion furnace and distillation device. The complete device can independently complete the material orders, including sample digestion and distillation. Titration and calculations. Typical, such as ZDDN-II automatic Kjeldahl.

Here are some of the questions that are often asked when purchasing and using the nitrogen analyzer. We will answer them one by one. Of course, if your friends have better suggestions, please don't hesitate to enlighten me.

1. Q: What is the basic principle of operation of the Kjeldahl meter?

A: Kjeldahl uses a compound whose protein is nitrogen. When we heat and digest the sample together with concentrated sulfuric acid and a catalyst, the protein is digested by chemical substances, and then the decomposed ammonia and sulfuric acid combine to form ammonium sulfate. Ammonium sulfate is distilled under certain conditions and then absorbed with acid. At this point we use sulfuric acid or hydrochloric acid to supplement the acid that was consumed, which is the titration process. Then, according to the amount of acid consumed, it is converted into ammonia. From this, we can calculate the nitrogen content, and there is a certain proportional relationship between nitrogen and protein content.

2. Q: What are the basic steps of the Kjeldahl method?

Answer: The basic steps of the Kjeldahl method are divided into five steps: sampling, digestion, distillation, titration and calculation. Digestion and distillation are the focus of the entire nitrogen determination process. Digestion is generally carried out in the digester. The digital digester has a single-chip microcomputer to detect and control the temperature, and it can achieve gradient control of the temperature. The harmful gases such as SO2 overflowing from the digestive canal can be discharged into the sewer through the corresponding channels through the built-in sewage discharge pipe of the digester, which inhibits the emission of harmful gases and ensures the safety of the experimental personnel. The typical digestion time of the sample is 40 minutes.