纤维素/聚硅氧烷离子液体混合气相色谱固定相的制备

纤维素是液相色谱中应用十分广泛的一类固定相，可是由于涂渍性能不佳，纤维素在气相色谱中的应用鲜有报道。本论文首先通过酯化反应合成了脂溶性较好的三醋酸纤维素（CTA），然后与自制的聚硅氧烷离子液体（PIL-C12-NTf₂）混配，制备了含纤维素的气相色谱固定相（CTA@PIL-C12-NTf₂），并涂渍了毛细管柱。其柱效为3165 plates/m（110 ℃，萘，k=4.95）。麦氏常数及溶剂化参数模型的测试结果证明，该固定相属中强极性固定相，主要作用力是氢键碱性作用和偶极作用。值得注意的是，引入纤维素可明显改善三取代芳香化合物位置异构体及壬烷（C9）同分异构体的分离选择性。此外，该固定相对正构烷烃、醇、脂肪酸酯及邻苯二甲酸酯等也具有良好的分离选择性。该研究不仅初步展现了纤维素在分离选择性上的特点，而且也为探索纤维素衍生物在气相色谱中的应用提供了一条新的途径。

Preparation of mixed stationary phase of cellulose and polysiloxane ionic liquid for gas chromatography

Cellulose has been widely used to synthesize chiral stationary phases for liquid chromatography, but it is still absent in the family of stationary phases of gas chromatography due to its poor film-forming property. Based on the unique dissolution characteristic, ionic liquids provide a great chance to solve this problem. In this paper, cellulose triacetate (CTA) was synthesized, and then mixed with the home-made polysiloxane ionic liquid (PIL-C12-NTf₂) to produce a novel mixed stationary phase (CTA@PIL-C12-NTf₂). After that, it was used to prepare a capillary column for gas chromatography. The column efficiency was measured to be 3165 plates/m (110 ℃, naphthalene, k=4.95), demonstrating the excellent film-forming capability of this stationary phase, and then the solvation parameter model was employed to find out the interaction parameters of CTA@PIL-C12-NTf₂. In the aspect of selectivity, CTA was firstly demonstrated to be able to improve the resolutions of tri-substituted aromatic positional isomers and the six isomers of nonane (C9). Moreover, some mixtures of representative chemicals like di-substituted aromatic positional isomers, n-alkanes, alcohols, aliphatic esters and phthalates can also be separated well on CTA@PIL-C12-NTf₂. This work proposed a novel way for the application of cellulose modified stationary phase of gas chromatography, and revealed some features of this stationary phase in selectivity resulting from cellulose.