【作者】 吴珧萍；

【导师】 陈天朗；

【作者基本信息】 四川大学 ， 无机化学， 2003， 硕士

【摘要】 我们在以传统甲醛—硫酸法分析硝酸脲中酰胺态氮时，发现酰胺态氮的含量总是与理论值相差将近1倍，有极大的“氮亏”(或“氮损”)现象。通过实验发现硝酸根与尿素共存时，它们在酸性条件下会定量地发生一系列的反应，找到了这些反应间的定量关系，并从反应温度、时间等方面进行多次试验，取得了一系列数据，找到了适宜的分析条件。我们还对传统的甲醛—硫酸法进行了改良，并将新的甲醛—硫酸法运用于硝酸尿素金属络合物中的酰氨态氮和总氮含量的测定中。我们从反应温度、时间等方面进行多次试验，找到了适宜的分析条件，取得了一系列数据，证明了该方法测定硝酸尿素金属络合物中氮含量的可行性。我们也将改进后的甲醛—硫酸法运用于硝酸盐中的常量硝态氮含量测定。我们通过外加一定量的已知酰态氮含量的尿素，通过甲醛法测定酰氨态氮含量，根据酰氨态氮损失量可以求得硝酸根含量。我们从反应温度、时间等方面进行多次实验找到了适宜的分析条件，取得了一系列数据，证明了该方法的可行性。更多还原

【Abstract】 When we used the formol-H2SO4 method to titrate the determinations of the content of amide nitrogen in urea nitrate, in which there is coexistence of amide nitrogen an nitric nitrogen, it was found that the results of amide nitrogen obtained were only equal to half of the theoretical values. It was deduced that the cause of this error is due to a side reaction happened among urea, nitrate ion and sulfuric acid, leading to a quantitative loss of urea. The mechanism of the deduced side reaction was verified experimentally by gasometry of the nitrogen liberated in the reaction. Based on the experimental facts, a modification for the calculation of results of conventional titrimetric method was proposed, which was proved to be more reasonable. The effects of analytical conditions, i.e. the temperature in the decomposition by H2SO4 and the time for decomposition were also studied, and optimum conditions of analytical procedure were thus presented. We also improved the conventional formol-H2SO4 titrimetric method, and applied it into the determinations of the contents of amide nitrogen and total nitrogen in urea nitrate metal complexes. Using the quantitative relationship of side reactions among urea, nitrate ion and sulfuric acid, we analyzed the content of amide nitrogen in urea nitrate metal complex by the use of formol titration method. We also experimented many times from aspects such as reaction temperature, reaction period, and so on. We had got the most suitable analytical conditions and a series of data to certify thefeasibility of this method. We also applied this urea-formol titric method into the determinations of the contents of nitric nitrogen in nitrate. We added certain urea whose content of amide nitrogen was known into the nitrate. From the losing of amide nitrogen we could calculate the content of nitric nitrogen. The analytical conditions such as reaction temperature, reaction period, and so on also had been studied. The most suitable analytical conditions and a series of data had been researched, to certify the feasibility of this method.更多还原