A set of new mixed-mode ion-exchange stationary phases is presented. The backbone of organic selectors is formed by a linear hydrocarbon chain, which is divided into two parts of various lengths by a heteroatom (oxygen or nitrogen). In all studied cases, there is a sulfonic acid moiety as the terminal group. Therefore, selectors bearing oxygen gave rise to strong cation ion-exchange stationary phases, while selectors with an embedded nitrogen atom (inducing a weak anion exchange capacity) were used to create zwitterion ion-exchange stationary phases. The new mixed-mode stationary phases were chromatographically evaluated in high performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC) using isocratic elution conditions to disclose their chromatographic potential. In HPLC mode, aqueous-rich reversed phase chromatography, acetonitrile-rich hydrophilic interaction liquid chromatography and methanolic ion-exchange chromatography mobile phases were employed. In these chromatographic modes, retention factors and selectivity values for a test set of basic and zwitterionic analytes were determined. The results were compared and principal component analysis for each chromatographic mode was performed. For all chromatographic modes, the component 1 in the principal component analysis reflected the elution order. The application of different mobile phases on a particular column resulted not only in variation in retention, but also in modified selectivity, and different elution order of the analytes. The orthogonality of the elution order depending on the employed mobile phase conditions was especially reflected for structurally closely related analytes, such as melatonin and N-acetyl-serotonin, tryptamine and serotonin or noradrenalin and octopamine. However, ion-exchange interactions remain the main driving force for retention. From all investigated stationary phases, the SCX 2 (C5-linker and C4-spacer) seems to be the best choice for the separation of basic analytes using different mobile phase conditions.

提出了一组新的混合模式离子交换固定相。有机选择剂的主链由直链烃链形成，直链烃链被杂原子（氧或氮）分为不同长度的两个部分。在所有研究的情况下，都有磺酸部分作为末端基团。因此，带有氧的选择器产生强阳离子交换离子的固定相，而带有嵌入氮原子的选择器（诱导弱的阴离子交换能力）被用来产生两性离子交换离子的固定相。使用等度洗脱条件在高效液相色谱（HPLC）和超临界流体色谱（SFC）中对新的混合模式固定相进行色谱分析，以揭示其色谱潜力。在HPLC模式下，富水反相色谱 采用富乙腈亲水相互作用色谱和甲醇离子交换色谱流动相。在这些色谱模式下，确定了碱性和两性离子分析物测试集的保留因子和选择性值。比较结果并进行每种色谱模式的主成分分析。对于所有色谱模式，主成分分析中的成分1反映了洗脱顺序。在特定的色谱柱上使用不同的流动相不仅会导致保留率变化，而且还会导致选择性变化，以及分析物的洗脱顺序不同。对于结构上密切相关的分析物，尤其反映了洗脱顺序的正交性，具体取决于所采用的流动相条件。例如褪黑素和N-乙酰基5-羟色胺，色胺和5-羟色胺或去甲肾上腺素和章鱼胺。但是，离子交换相互作用仍然是保留的主要驱动力。在所有研究的固定相中，SCX 2（C5接头和C4垫片）似乎是使用不同流动相条件分离碱性分析物的最佳选择。