一、酰氨态氮和硝态氮共存时氮含量测定的研究 二、还原法生产无氯二氧化氯及联产无机盐新工艺和二氧化氯稳定化的研究
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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。
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 the
feasibility 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.
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 the
feasibility 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.
引文
[1] GB2441-81．尿素总氮含量的测定方法(蒸馏法)
[2] GB3598-83．肥料中酰氨态氮的测定(尿素酶法)
[3] GB2442-81．尿素总氮含量的测定(甲醛法)
[4] 武汉大学．分析化学[M]．北京：高等教育出版社，1997
[5] 范红松．固体解磷剂解磷能力及机理研究[T]．四川大学硕士学位论文，1993
[6] 陈天朗，肖慎修．用固体解磷剂干法制氮磷复合肥[J]．磷肥与复肥，1989(3)：11
[7] 陈天朗，肖慎修．从固体解磷剂干法制复肥谈我国化肥发展战略[J]．四川化工，1990(2)：19
[8] 陈天朗．一种氮磷复肥的生产方法[P]．中国发明专利，87 103006．3．
[9] Chen Tian-lang, Xiao Shen-xiu, Li Ping. Int J. Quant. Chem. 1997 (64): 247
[10] [苏]М．Н．纳比耶夫著，孙挢，丁德，陈明磊译．硝酸磷肥(上册)[M]．北京：化学工业出版社，1980：16
[11] 汪明远．硝酸磷肥的生产与发展[J]．磷肥与复肥，2000(4)：1
[12] 陈天朗，范红松，肖慎修．干法硝脲磷肥[J]．磷肥与复肥，1997(4)：14
[13] 陈寿椿．重要无机化学反应[M]．上海：上海科学技术出社，1982．1073～1074．
[14] 陈天朗．介绍一种新铁肥—尿素铁[J]．化肥工业，1980(1)：69
[15] [英]W．J威廉斯著，曲长菱，齐大勇译．阴离子测定手册[M]．北京：冶金工业出版社，1987：161
[16] 吴珧萍，陈天朗，陈慧等．硝酸脲中的酰胺态氮及总氮含量测定的研究[J]理化检验—化学分册，2002，38(3)：111
[17] Lawrence. H. Dalman. J. Am. Chem. Soc. 1943 (56), 549-53
[18] 吴珧萍．牟元华，陈天朗等．尿素—甲醛法测硝酸尿素金属络合物中酰氨态氮和总氮含量的研究[J]．分析试验室，2003(5)
[19] 吴珧萍，牟元华，陈天朗等．测定常量硝酸根离子的新方法——尿素-甲醛法[J] 理化检验—化学分册(待发)
[20] 陈寿椿．重要无机化学反应[M]．上海：上海科学技术出版社，1982．1072
[21] 天津市化工研究院等编．无机盐工业手册[M]．北京：化学工业出版社，1979．874
[22] 天津市化工研究院等编．无机盐工业手册[M]．北京：化学工业出版社，1979．888
[2] GB3598-83．肥料中酰氨态氮的测定(尿素酶法)
[3] GB2442-81．尿素总氮含量的测定(甲醛法)
[4] 武汉大学．分析化学[M]．北京：高等教育出版社，1997
[5] 范红松．固体解磷剂解磷能力及机理研究[T]．四川大学硕士学位论文，1993
[6] 陈天朗，肖慎修．用固体解磷剂干法制氮磷复合肥[J]．磷肥与复肥，1989(3)：11
[7] 陈天朗，肖慎修．从固体解磷剂干法制复肥谈我国化肥发展战略[J]．四川化工，1990(2)：19
[8] 陈天朗．一种氮磷复肥的生产方法[P]．中国发明专利，87 103006．3．
[9] Chen Tian-lang, Xiao Shen-xiu, Li Ping. Int J. Quant. Chem. 1997 (64): 247
[10] [苏]М．Н．纳比耶夫著，孙挢，丁德，陈明磊译．硝酸磷肥(上册)[M]．北京：化学工业出版社，1980：16
[11] 汪明远．硝酸磷肥的生产与发展[J]．磷肥与复肥，2000(4)：1
[12] 陈天朗，范红松，肖慎修．干法硝脲磷肥[J]．磷肥与复肥，1997(4)：14
[13] 陈寿椿．重要无机化学反应[M]．上海：上海科学技术出社，1982．1073～1074．
[14] 陈天朗．介绍一种新铁肥—尿素铁[J]．化肥工业，1980(1)：69
[15] [英]W．J威廉斯著，曲长菱，齐大勇译．阴离子测定手册[M]．北京：冶金工业出版社，1987：161
[16] 吴珧萍，陈天朗，陈慧等．硝酸脲中的酰胺态氮及总氮含量测定的研究[J]理化检验—化学分册，2002，38(3)：111
[17] Lawrence. H. Dalman. J. Am. Chem. Soc. 1943 (56), 549-53
[18] 吴珧萍．牟元华，陈天朗等．尿素—甲醛法测硝酸尿素金属络合物中酰氨态氮和总氮含量的研究[J]．分析试验室，2003(5)
[19] 吴珧萍，牟元华，陈天朗等．测定常量硝酸根离子的新方法——尿素-甲醛法[J] 理化检验—化学分册(待发)
[20] 陈寿椿．重要无机化学反应[M]．上海：上海科学技术出版社，1982．1072
[21] 天津市化工研究院等编．无机盐工业手册[M]．北京：化学工业出版社，1979．874
[22] 天津市化工研究院等编．无机盐工业手册[M]．北京：化学工业出版社，1979．888