The ion-exchange and complex forming equilibria were quantitatively described and demonstrated in order to understand major factors in the control of selectivity in the analytical separation of carboxylic acids and inorganic anions in cryptand based ion chromatography. A complex retention model has been developed for the separation on a non-conventional IC column. Changes in retention are treated both theoretically and experimentally. Retention mechanism is employed on a macrocycle-based (cryptand n-decyl-[2.2.2]) ion-exchange chromatographic phase to improve the selectivity for a mixture of model analytes. We introduced an alternative internal gradient method by mixed eluent (i.e. eluents formed by combination of two alkali hydroxide with different molar ratio). The effect of binary mixed eluent (Li/Na, Li/K) on the retention behavior and peak shape of carboxylic acids are also discussed in view of the proposed theory. It was shown that the effects of binary aqueous mobile phases, held isocratically behave very similar to the step gradient mode. The "internal gradient" separation system has advantages over traditional step gradient mode. Twenty-six anions of widely varying chemical character (mono-, di-, tri-valent inorganic anions, mono-, di-, tri-valent aliphatic carboxylic acids, aromatic- and haloacetic carboxylic acids) were investigated on the cryptand-based (D222) stationary phase using different methods by LiOH, NaOH and KOH eluent. The predicted vs measured retention data are in rather good agreement. High degree of linearity was obtained for inorganic anions, multivalent carboxylic acids, and for aromatic and haloacetic acids R2 = 0.992, 0.969, and 0.980, respectively.

中文翻译：

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开发了基于隐穴离子色谱分离羧酸和无机阴离子的保留机理。

定量描述和证明了离子交换和络合物形成的平衡，以了解在基于穴根的离子色谱法中分析分离羧酸和无机阴离子时控制选择性的主要因素。已经开发出了一种复杂的保留模型，用于在非常规IC色谱柱上进行分离。保留率的变化在理论上和实验上都得到了处理。保留机制用于基于大环的（cryptand n-decyl- [2.2.2]）离子交换色谱相，以提高对模型分析物混合物的选择性。我们通过混合洗脱液（即由摩尔比不同的两种碱金属氢氧化物混合形成的洗脱液）介绍了一种内部梯度洗脱方法。二元混合洗脱液（Li / Na，Li / K）对羧酸的保留行为和峰形也进行了讨论。结果表明，等度地保持的二元水性流动相的作用与阶跃梯度模式非常相似。“内部梯度”分离系统具有优于传统阶梯梯度模式的优势。在以隐链为基础的分子筛上研究了26种化学性质各异的阴离子（一价，二价，三价无机阴离子，一价，二价，三价脂肪族羧酸，芳族和卤代乙酸羧酸）。 D222）固定相，采用LiOH，NaOH和KOH洗脱液的不同方法。预测保留值与测量保留值的数据非常吻合。无机阴离子，多价羧酸，