Answer: After setting the corresponding experimental parameters, the automatic Kjeldahl azotometer does not need manual intervention in the whole experimental process. Compared with the traditional manual device, it has many advantages, such as fast test speed, high efficiency, high accuracy of sample test results, good repeatability, low risk factor and so on.
Q2. What are the classifications and differences of common Kjeldahl nitrogen determination instruments in the market?
Answer: There are many classifications in the market at present. The most common classifications are: 1. Semi-automatic azotometer: it only supports automatic filling of some reagents or does not support automatic filling of reagents, supports automatic timing distillation, and needs manual titration for titration; 2. Automatic Kjeldahl apparatus: The apparatus can automatically complete automatic dilution, automatic alkali addition, automatic water supplement, automatic acid addition and automatic distillation, and manual titration is required for titration; 3.Automatic Kjeldahl apparatus: integrated design of distillation and titration, automatic dilution, automatic alkali addition, automatic water supplement, automatic acid addition, automatic titration and result calculation and printing after the sample is completely digested. Some instruments can also support automatic sampling function, the whole experimental process without human intervention, greatly reducing the workload of laboratory personnel, improving work efficiency, and the test results are more accurate.
Q3.Which industries are the main applications of the azotometer?
Answer: The azotometer is mainly used for nitrogen/protein content, volatile base nitrogen, soil cation exchange capacity, acrylonitrile content in rubber, etc. In samples from food, feed, agriculture, scientific research institutes, medicine, universities, chemical industry, environment and other industries.
Q4.How to test the accuracy of the instrument?
Answer: "GB/T 33862-2017 Full (Half) Automatic Kjeldahl Nitrogen Determination Instrument" has clear requirements for the recovery rate and repeatability of the machine, and the accuracy and repeatability of the machine can be verified regularly by using ammonium sulfate of different concentrations according to the method in the standard.
Q5. How to select the appropriate titration precision?
Answer: The general titration accuracy of the automatic Kjeldahl apparatus refers to the minimum titration volume, most of which is 1-2 μL/step, and some of which can reach 0.2 μL/step or lower. The titration precision is 1-2 μL/step, which is more than 10 times higher than that of manual method, and can meet the needs of most samples.2Titration precision of μL/step or higher is mainly for special samples such as very low content. At the same time, in theory, the titration accuracy is inversely proportional to the titration rate. When titrating the same volume, the higher the titration accuracy, the longer the time required. Therefore, it is recommended to select the appropriate titration accuracy according to the sample condition.