Kjeldahl analyzer has a high-precision color sensor to determine the end point, intelligent program control, can automatically complete dilution with water, add acid, alkali, distillation, titration, titration cup automatic drainage cleaning, digester emptying, result calculation and output Print results without the need for human intervention throughout the entire process, and the advantages of accurate and reliable data. The entire process takes only 5 minutes, while conventional total nitrogen distillation and semi-micro distillation require 20 minutes or more. Therefore, the Kjeldahl meter has great advantages and application prospects in the determination of protein content in the fields of food, chemical industry, agriculture and animal husbandry, medicine and health. The results showed that the determination of total nitrogen in fertilizers was improved by the improved digestion method. The test results were very repeatable. The error of parallel determination was much smaller than the current allowable difference of national standards for compound fertilizers. There is a good consistency with the test results of the current national standard method. Related equipment: digestion furnace EVA Embossed Sheet is also called micro dot sheet, made by a roller heat press for the surface texture. It has same function as the EVA Faux Teak Sheet, providing a non-skid feature and perfect protection for boat. Eva Embossed Sheet,Coaming Bolster Pads,Embossed Eva Foam Sheet,Eva Coaming Pads,Embossing Eva Rubber Sheets,Eva Boat Flooring Sheet Huizhou City Melors Plastic Products Co., Limited , https://www.thefoammaster.com
Nitrogen fertilizer has a significant impact on the growth and yield of potato and wheat. In agricultural ecosystems, carbon and nitrogen can increase soil fertility and crop yield through the circulation of soil organic matter. At the same time reducing the negative effects of the environment, so it is very important to quickly measure the total nitrogen content of chemical fertilizers. Digestion technology is a bottleneck restricting the development of the automatic Kjeldahl nitrogen analyzer. Because compound fertilizers contain various forms of nitrogen such as nitrate nitrogen, ammonium nitrogen, organic nitrogen, urea nitrogen, and cyano-ammonium nitrogen, the digestion of total nitrogen in compound fertilizers is more complex than that of single-form nitrogen. It is necessary to conclude an easy-to-operate, accurate, and rapid digestion method that is suitable for the fully automatic Kjeldahl analyzer.
In this study, the current national method of fertilizer nitrogen determination and the digestion manual of Foss (Foss) were used to improve the digestion method, which overcomes the bottleneck of the automatic Kjeldahl nitrogen analyzer to a certain degree, and makes use of the automatic Ky The determination of total nitrogen in compound fertilizers by the nitrogen analyzer is faster, more accurate, and easier to operate.
1 Materials and Methods
1.1 Digestion Principles The nitrates in compound fertilizers are reduced to ammonium salts by the addition of concentrated hydrochloric acid under the action of a catalyst nitrogen-fixing alloy, and are digested with concentrated sulfuric acid to convert organic nitrogen or urea nitrogen and cyanamide nitrogen into sulfuric acid. Ammonium.
1.2 Reagents The reagents are double distilled water; the nitrogen-fixing alloys (Cu, Al, and Zn contents of 50%, 45%, and 5%, respectively) and other calibration and reagents used are the same as GB/T 8572.
1.3 Instruments
Kieltec 8400 automatic Kjeldahl nitrogen analyzer; TecatorTM digestion system.
1.4 Experimental method Weigh 0.100 0-0.200 0 g of compound fertilizer sample into distillation tube of 250 mL distiller. Add 35 mL of distilled water to shake the sample and add 1.0 g of nitrogen-fixing alloy. , 7 mL concentrated hydrochloric acid, placed in a distillation flask Tecato a digestion device. Heat to 150°C. The distillation tube was removed and cooled on the digester rack to room temperature and reacted for 20 minutes. Then add 10 mL concentrated sulfuric acid. The distillation tube was placed on the digester and digested at 480°C. After the distillation tube was clear and translucent and a small amount of sulfuric acid white smoke began to rise, the distillation tube and the digestion tube rack were removed and cooled to room temperature in a fume hood. Add 10.20 mL distilled water to continue distillation at 100 °C in the distillation tube. When the solution in the distillation tube is bright and transparent blue solution, remove the distillation tube and cool to room temperature, and evaporate on the automatic Kjeldahl apparatus.
2 Results and Analysis
2.1 Analysis of ammonium nitrate total nitrogen content In the determination of the total nitrogen content of compound fertilizer, ammonium nitrate is often used as the spiked sample and verification test sample, so the degree of ammonium nitrate digestion and nitrogen determination often determine the total nitrogen of compound fertilizer. Content determination data. Table 1 lists the results obtained by different methods such as ammonium nitrate GB method, FOSS company digestion manual method (abbreviated as FOSS method), and the digestion improvement method used in this experiment (abbreviated as improvement method). 
From Table 1, it can be seen that the use of national standard method to digest a long time, a large amount of reagents. Although the FOSS method is relatively small in the digestion time and the amount of reagents. However, since ammonium nitrate contains nitrate nitrogen, the FOSS method lacks the step of reducing nitrate nitrogen, so the nitrogen content is only 16.98%. Compared with the national standard method and the FOSS method, the improved method not only has a short digestion time, but also has a small amount of reagents. Moreover, the determination of nitrogen content is close to the theoretical value.
2.2 Determination of nitrogen content of five kinds of commercially available compound fertilizers Five different compound fertilizers sold on the market were selected and sampled according to the method of the literature, and digested in accordance with the current national standard method and improved method. The compound fertilizer digested by the national standard method was semi-micro Nitrogen fixed nitrogen. The modified compound digested fertilizer was measured on the automatic Kjeldahl nitrogen analyzer for the determination of total nitrogen content. The different digestion methods for the nitrogen content of the five compound fertilizers are shown in Table 2. 
2.3 Analysis of distillation titration conditions of automatic Kjeldahl apparatus According to the titration conditions provided by FOSS, the addition of 40% NaOH solution is the key to distillation titration. After adding 40% Na0H strain to black solution. The addition of NaOH is too easy to consume reagents. Too little addition will not completely neutralize the sulfuric acid and cannot be measured. Therefore, it is reasonable to add 30 mL. Before the titration, a small amount of water must be added to the distillation tube for proper digestion to make the sample appear bright and transparent blue solution. Otherwise, in the distillation titration may occur when steaming is not nitrogen or steam is not complete, because the high temperature digestion makes the fertilizer sample and the nitrogen-fixing alloy mixed with each other at the bottom of the distillation tube, so that the ammonium sulfate can not be completely dissolved in the aqueous solution Causes the distillation to be incomplete or incomplete.
3 Summary and discussion The automated Kjeldahl nitrogen analyzer simplifies the steps for the determination of protein or total nitrogen content, shortens the analysis time, and improves work efficiency. However, due to the lag of the digestion method, the use efficiency of the automatic Kjeldahl tester is restricted. This study used the reference of the national standard digestion method and FOSS elimination to show the personality characteristics. It embodies the public's perception and evaluation of the brand, especially consumers. Therefore, the brand image has meaning only if it is communicated to consumers through sales or promotional activities. On the one hand, companies in the region should do a good job of public relations and form a good image of the brand as soon as possible; on the other hand, they can consciously introduce the brand image to the public through various media. The promotion of regional brand image includes oral communication by regional customers, celebration of major festivals, holding of project promotion meetings, investment invitations, trade fairs, fairs, and exhibitions. Establish industry internet websites, open up professional forums and lectures, etc.
The agricultural regional brand is an important intangible asset and a great asset for its owners. In order to prevent this huge intangible asset and valuable wealth from being infringed, relevant departments must implement effective protection strategies for the brand. Regional brands have the characteristics of public goods, which provide incentives for companies in the region to “free riders†and also provide opportunities for companies in and outside the region to act as sub-consumers. Finally, the overall image of regional brands is damaged. In order to effectively prevent all kinds of violations and infringements. Enterprises in the region should formulate various protection measures to maintain regional brands.
3.3 Play the main role of leading enterprises in the regional brand building The regional brand is often a comprehensive embodiment of corporate brand collective behavior in a certain area, represents the main body and image of a regional industry brand, and plays a decisive role in the economic development of the region. effect. Creating and developing a regional brand is essentially a business operation. A large number of enterprises and industrial brands in the region are required to participate collectively. The enterprise is the main body for the creation and development of regional brands. It is also the biggest beneficiary of regional brand development. The company’s own products and brand image are the basis for the development of regional brands. Therefore, companies in the region must establish and strengthen brand awareness. Continuously improve the quality of products and services. We will intensify scientific and technological innovation, explore the connotation of product brands, increase the overall competitiveness of products, and promote industrial upgrading. At the same time, we will strengthen independent innovation of enterprises and build their own brands to promote the development of regional brands.
3.4 Increase the degree of organization. Promoting Cooperative Marketing Increasing the degree of farmers' organization and encouraging farmers to carry out cooperative marketing play an important role in prompting farmers to walk out of the pattern of small-scale agriculture, promote the development of agricultural specialization, and reduce farmers' access to such information and information. To this end, it is necessary to strengthen the guidance on the basis of respecting the wishes of farmers, carry out education and training, and enhance farmers' awareness of cooperation. Strengthen the promotion and application of agricultural science and technology, and improve the farmers’ ability to cooperate: Second, formulate relevant policies, and grant preferential cooperation policies to farmers in terms of registration, registration, financial support, tax incentives, financial and insurance support, etc. Supporting efforts: Third, we must pay attention to the cultivation and use of management personnel in agricultural cooperatives. If cooperative organizations are to play a role, they must focus on cultivating and cultivating a large number of agricultural management personnel while paying attention to cooperation in the construction of hardware facilities. And to create conditions for them to help lead the majority of cooperative economic organizations and peasants to achieve prosperity.
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