重氮化剂对分光光度法测定大气降水中亚硝酸盐影响的研究

Study on the effect of using diazotization agent to determine nitrite in the wet precipitation by spectrophotometry

在对分光光度法测定大气降水中亚硝酸盐进行比对研究基础上,对分析方法所用重氮化剂做了优化性选择。以不同的重氮化剂,对分析方法从显色络合物的吸收光谱、校准曲线、试剂空白试验、标准样品的实际测定,以及分析方法的精密度和准确度等方面进行比对分析。根据比对分析结果,选择出最佳性能的重氮化剂。实验结果表明,以对氨基苯磺酰胺作为分析方法的重氮化剂,测定的精密度好、准确度高,降低了试剂空白,提高了测定灵敏度。从技术指标分析,作为重氮化剂,对氨基苯磺酰胺的重氮化性能优于对氨基苯磺酸,是《大气降水中亚硝酸盐测定N-(1-萘基)-乙二胺光度法》等标准分析方法中重氮化剂的最佳选择。

The diazotization agent for the analysis of nitrite in the wet precipitation by spectrophotometry was optimized on the basis of comparative study in the aspect of the absorption spectrum of chromogenic complex, the calibration curve, the reagent blank experiment, the measurement of standard sample, and the precision and the accuracy of analysis method. The best- performing diazotization agent was selected, according to the results of the comparative analysis. The experiment results showed that, using sulfanilamide as the diazotization agent, the analytical method performed good precision and accuracy, meanwhile, the reagent blank was reduced and the sensitivity was enhanced. Through the analysis of technical indicators, sulfanilamide served as the diazotization agent showed better diazotization performance comparing to p-aminobenzene sulfonic acid, and could be used as the optimal choice of the diazotization agent for the standard analytical methods, such as ＂Determination of N-（ 1-naphthyl）-l, 2-diaminoethane dihydrochloride through nitrite in the wet precipitation by spectrophotometry＂.