草酸二甲酯中硝酸根的检测

Determination of Nitric Acid in Dimethyl Oxalate

离子色谱分析技术是在近年来发展得比较快的一项分析方法,它具有灵敏度高、分析速度快、选择性好、试样用量少、能实现同时测定多组分和不同价态化合物的离子、易实现自动化等优点。离子色谱主要被用来研究测定无机阴阳离子,本文主要建立了离子色谱测定草酸二甲酯中硝酸根含量的分析方法。该方法通过水解和氧化草酸二甲酯样品的预处理手段,消除样品复杂基体和样品水解生成草酸根对硝酸根测定的干扰,选用赛默飞AG23+AS23阴离子色谱柱,以4.5 mmol Na_(2)CO_(3)+0.8 mmol NaHCO3混合溶液作为淋洗液,离子色谱峰不仅分离良好,且16 min即可完成分析。该方法在硝酸根质量浓度6.25~100 mg/L范围内线性方程为y=0.1036x-0.2896,R2=0.9991,测得实际样品硝酸根含量相对标准偏差RSD为1.5278%(n=4),完全满足化工生产中间控制分析的及时性和准确性要求。

Ion Chromatography is an analytical method that has developed rapidly in recent years,it has the advantages of high sensitivity,fast analysis speed,good selectivity,less sample amount,simultaneous analysis and determination of multi-component and different valence compounds,and easy to realize automation.Ion chromatography is mainly used to study inorganic anions and cations.A method for the determination of nitrate in dimethyl oxalate by ion chromatography was developed.In this method,the sample was pretreated by hydrolysis and oxidation of dimethyl oxalate to eliminate the interference of the complex matrix of the sample and the hydrolysis of the sample to oxalate to the determination of nitrate,using 4.5 mmol Na_(2)CO_(3)+0.8 mmol NaHCO3 as eluent,the ion chromatogram not only separated well,but also completed the analysis in 16 minutes.The linear equation y=0.1036x-0.2896,R2=0.9991 in the range of 6.25~100 mg/L nitrate concentration,and the RSD of actual sample nitrate content was 1.5278%(n=4),it can meet the requirement of timeliness and accuracy of chemical production control analysis.