Waters Corporation, Milford, MA 01757, USA.
J Sep Sci. 2010 Mar;33(6-7):740-51. doi: 10.1002/jssc.200900660.
A comprehensive retention and selectivity characterization of several hydrophilic interaction chromatography (HILIC) stationary phases was performed with 28 test probes in order to study the influence of particle type, surface chemistry, and mobile-phase pH on chromatographic retention, selectivity, and MS response. Selectivity differences were compared for columns operated at both low and high pH, while ESI-MS was used to study the effects of mobile-phase pH on signal response. Additionally, acetone was explored as a potential alternative to ACN as the weak HILIC solvent. Moderate differences in selectivity were observed on the same column operated at different pH, mostly due to acidic compounds. In addition, the MS response increased when a high pH mobile phase was used, particularly for analytes that were ionized with negative ESI-MS. Even larger selectivity differences were observed for different stationary phases evaluated with the same mobile phase. Acetone was not a suitable replacement for ACN in routine HILIC separations due to differences in selectivity and MS response. Finally, the data from this study were used to establish guidelines for rapid HILIC method development of polar compounds, which is demonstrated with a mixture of histidine dipeptides and organophosphonate nerve agent metabolites.
为了研究颗粒类型、表面化学和流动相 pH 值对色谱保留、选择性和 MS 响应的影响，对 28 种测试探针进行了全面的保留和选择性特征描述，对几种亲水相互作用色谱（HILIC）固定相进行了研究。比较了在低 pH 和高 pH 值下运行的柱子的选择性差异，同时使用 ESI-MS 研究了流动相 pH 值对信号响应的影响。此外，还探索了将丙酮作为替代乙腈的潜在弱 HILIC 溶剂。在不同 pH 值下使用相同的柱子时观察到选择性有适度差异，主要是由于酸性化合物。此外，当使用高 pH 值的流动相时，MS 响应增加，特别是对于用负离子 ESI-MS 电离的分析物。用相同的流动相评估不同的固定相时，还观察到更大的选择性差异。由于选择性和 MS 响应的差异，丙酮不适合替代乙腈用于常规 HILIC 分离。最后，该研究的数据用于建立快速 HILIC 极性化合物方法开发的指南，并用组氨酸二肽和有机膦神经毒剂代谢物混合物进行了演示。
