等度淋洗离子色谱法测定醇胺溶液中的七种热稳定盐

Determination of seven heat stable salt anions in alkanolamine solution by isocratic elution ion chromatography

关键词:  离子色谱  热稳定盐  醇胺  等度淋洗

Key words:  ion chromatography  heat stable salt  alcohol amine  isocratic elution

摘要:

采用等度淋洗离子色谱法,建立一种同时测定以N-甲基二乙醇胺为代表的醇胺溶液中热稳定盐含量的分析方法。该方法将用去离子水稀释、0.45 μm膜过滤后的醇胺溶液样品,在优化的离子色谱淋洗条件(2 mmol/L Na₂CO₃ + 8 mmol/L NaHCO₃)下分离和检测,外标法定量,实现了甲酸根、氯离子、硝酸根、硫酸根、硫氰酸根、草酸根和硫代硫酸根等7种热稳定盐的同时测定。方法 学研究结果表明,各离子质量浓度在5~80 μg/mL范围内线性良好,相关系数均大于0.999 5,精密度(RSD)均小于5%,3个质量浓度添加水平的回收率在85%～98%之间。应用该方法成功测定了5份样品中7种热稳定盐的含量。建立的测定醇胺溶液中的7种热稳定盐含量的分析方法前处理简单、重复性好、结果准确,具有较强的可靠性和实用性。 

Abstract:

An analytical method for simultaneous determination of heat stable salts in alkanolamine solutions represented by N-methyldiethanolamine was established by isocratic elution ion chromatography. In this method, the sample of alkanolamine solution diluted with deionized water and filtered by 0.45 μm membrane was separated and detected under the optimized ion chromatographic elution conditions (2 mmol/L Na₂CO₃ + 8 mmol/L NaHCO₃), and quantified by external standard method, thus realizing the simultaneous determination of seven heat stable salt anions such as formate, chloride, nitrate, sulfate, thiocyanate, oxalate and thiosulfate. Methodological results showed that the linearity of each ion was good in the concentration range of 5-80 μg/mL, the correlation coefficient was greater than 0.999 5, the precision(RSD) was less than 5%, and the recovery rate of three concentration levels was between 85%-98%. The method has been successfully applied to the determination of seven heat stable salt anions in five samples. The analytical method for determination of seven kinds of heat stable salts in alkanolamine solution established in this work is simple in pretreatment, good in repeatability, accurate in results, reliable and practical.