无水硝酸中N2O4和N2O5含量的分析

采用滴定法和滴定与核磁共振(NMR)谱相结合的方法分析了N2O4N2O5HNO3体系各组分的含量,并对滴定法和滴定与NMR谱相结合法的分析结果进行了比较,研究了不同的氧化剂、取样方式以及不同的溶剂对分析结果的影响。结果表明滴定法和滴定与核磁共振光谱相结合法分析N2O4N2O5HNO3体系是可行的。硫酸铈作为氧化剂较高锰酸钾作为氧化剂的分析结果准确度高;安瓿球取样较移液管取样分析结果准确;纯水作为溶剂较氢氧化钠作为溶剂的分析结果的重现性好、准确度高。

Two Methods for Analyzing N2O4 and N2O5 in Anhydrous HNO3

The concentrations of tetroxide dinitrogen (N_2O_4)and pentoxide dinitrogen(N_2O_5) and nitric acid in N_2O_4-N_2O_5-HNO_3 system are measured by the chemical titration and the nuclear magnetic resonance spectra (NMR)combining titration,respectively. And its results from two methods were compared. The effects of the oxidants,the solvents and the sampling methods on the concentrations of N_2O_4,N_2O_5 analyzed by the chemical titration were also investigated. The results indicate that both the NMR combining titration and titration are in agreement and accurate for the analysis of N_2O_4-N_2O_5-HNO_3 system. N_2O_4 concentrations analyzed by using cerium sulfate as oxidant are more accurate than that of potassium hypermanganate as oxidant. The results of sampling by using ampoule ball are better than that of sampling by using pipette. Comparing with the aqueous solutions of sodium hydroxide as solvent to analyze N_2O_5 concentration,distilled water used as solvent gives the higher accuracy and the better repeatability.