Method for measuring content of total nitrogen in urea-ammonium nitrate solution

Abstract

The invention relates to a method for measuring content of total nitrogen in a urea-ammonium nitrate solution containing 27%-33% of nitrogen. According to the method, concentrated sulfuric acid is added to the urea-ammonium nitrate solution, amide nitrogen is converted into ammonium nitrogen, a nitrogen-fixation alloy is added, nitrogen in various forms is sequentially converted into ammonium nitrogen, sodium hydroxide is added, ammonium nitrogen is converted into ammonia to be distilled, ammonia is absorbed with a boric acid solution, a standard sulfuric acid titration solution is used for direct titration, and the content of total nitrogen is calculated. Compared with an existing method of back titration after distillation and a method of direct titration after distillation, the method has the advantages that the steps are reduced, the operation is simpler, more convenient and more fast, the analysis procedure is greatly shortened, coexisting complicated matrix components, manual operation and other factors cause little influence on measurement, the interference capability of the method is enhanced, the accuracy and the precision of a result are improved, and the analysis and checking cost is very low.

Description

technical field [0001] The invention relates to a method for determining the total nitrogen content in urea ammonium nitrate solution with a nitrogen content of 27% to 33%. Background technique [0002] Urea Ammonium Nitrate solution (Urea Ammonium Nitrate solution), referred to as UAN solution, also known as nitrogen solution (N solution) abroad, is prepared from urea, ammonium nitrate and water. The nitrogen contents are ammonium nitrogen, nitrate nitrogen and amide nitrogen respectively. [0003] Urea ammonium nitrate solution is a new liquid nitrogen fertilizer. It is a mixed solution of urea and ammonium nitrate. The content of urea and ammonium nitrate directly affects the content and ratio of ammonium nitrogen, nitrate nitrogen and amide nitrogen, and also directly affects To the effect of using liquid fertilizer. Because the liquid fertilizer contains both inorganic nitrogen and organic nitrogen, the results of accurate and rapid analysis of ammonium nitrogen, nitr...

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Problems solved by technology

This method also has the disadvantages of long analysis time (2.5~3.0 hours), high digestion temperature (up to 380°C), and poor anti-interference ability of this method, poor control of digestion temperature will cause violent boiling, which is easy to damage Disadvantages of human injury and difficult control of airtightness, thus affecting the analysis results

[0007] The above methods all have defects such as many steps, long analysis process, weak anti-interference ability, and long analysis time (2.5~3.0 hours).

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