In this work, a novel imidazolium ionic liquid-functionalized poly(quinine)-modified silica stationary phase (Sil-PQn-MIm) was successfully synthesized via surface radical chain transfer and nucleophilic substitution reaction. The modified silica was confirmed by series of characterizations including Fourier transform infrared spectroscopy (FT-IR), elemental analysis (EA), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The multi-mode chromatographic performances of the Sil-PQn-MIm column were investigated by anion-exchange mode for separation of aromatic acid samples, hydrophilic interaction mode for separation of nucleosides/nucleobases and sulfanilamides, and reversed-phase mode for separation of alkylbenzenes, benzene and polycyclic aromatic hydrocarbons (PAHs), and the Tanaka test mixtures, respectively. As expected, compared to the Sil-PQn column only with quinine as functional group, the Sil-PQn-MIm column further modified by imidazolium ionic liquid possessed higher separation performance, especially for the separation of nucleosides/nucleobases. The effects including buffer concentration, pH, organic solvent content and column temperature on chromatographic performance were studied, which proved that multiple interactions including electrostatic, hydrophobic and hydrophilic interactions can be simultaneously existed between the stationary phase and the analytes. In addition, reproducibility and efficiency of the Sil-PQn-MIm column were also investigated, the results illustrated that the stationary phase have good enough reproducibility (RSDs 0.15%-0.72%, n = 7) and high efficiency (plates per meter, ~90000 plates/m). In conclusion, the prepared stationary phase with multiple-mode retention capabilities could realize separation for various types of samples by optimizing chromatographic conditions, even for some chiral compounds.

中文翻译：

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咪唑鎓离子液体增强的聚（奎宁）改性二氧化硅，是一种用于分离非手性和手性化合物的新型多模式色谱固定相。

在这项工作中，通过表面自由基链转移和亲核取代反应成功地合成了一种新型的咪唑鎓离子液体官能化的聚（奎宁）改性的二氧化硅固定相（Sil-PQn-MIm）。改性二氧化硅已通过一系列表征得到证实，包括傅立叶变换红外光谱（FT-IR），元素分析（EA），透射电子显微镜（TEM）和热重分析（TGA）。通过阴离子交换模式分离芳香酸样品，亲水相互作用模式分离核苷/核碱基和磺酰胺类化合物以及反相模式分离烷基苯，研究了Sil-PQn-MIm色谱柱的多模式色谱性能。苯和多环芳烃（PAH），以及田中测试混合物。不出所料，与仅以奎宁为官能团的Sil-PQn色谱柱相比，用咪唑鎓离子液体进一步改性的Sil-PQn-MIm色谱柱具有更高的分离性能，尤其是在分离核苷/核苷碱基方面。研究了缓冲液浓度，pH，有机溶剂含量和柱温对色谱性能的影响，证明了固定相与分析物之间可以同时存在多种相互作用，包括静电，疏水和亲水相互作用。此外，还研究了Sil-PQn-MIm色谱柱的重现性和效率，结果表明固定相具有足够好的重现性（RSDs为0.15％-0.72％，n = 7）和高效率（每米塔板数，〜 90000板/米）。结论，