离子色谱中高质量浓度的Cl^-对痕量NO_2^-,Br^-和NO_3^-测定的影响

Study on the Analysis of NO_2^-,Br^- and NO_3^- by Ion Chromatography in the Presence of High Mass Concentration of Chloride

在 3支不同性质的离子色谱柱上 ,研究了高质量浓度的Cl- 对痕量NO2 - ,Br- 和NO3- 分离分析的影响 ,提出在分离过程中同时存在自身洗脱效应和在柱流动相变化两种洗脱机理。当Cl- 与待测离子色谱峰重叠时 ,在抑制器处置换出的H+使弱酸型阴离子分子化 ,给定量测定带来偏差 ,而对于强酸型阴离子则没有影响。由实验得到用峰高法测定NO-2 ,Br- 和NO3- 等 3种阴离子时在不同Cl- 质量浓度下的线性范围以及能够准确定量的Cl- 的最大质量浓度。

The effects of high mass concentration chloride on the determination of NO\-2\+-,Br\+- and NO\-3\+- were studied on three different analytical columns by ion chromatography The variations of retention behavior of these anions were caused by self elution effect and on column eluent change in the presence of high concentration chloride When their peaks overlapped with chloride, the deviations of the quantity of weak acid anions were caused by anion proton interactions within the suppressor However, the strong acid anions and the other weak acid anions, not overlapped by chloride, were not affected The linear ranges of these anions in different concentrations of chloride and the maximum chloride concentration allowed to be measured by peak height quantitative method were examined