Abstract:

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.

Key words: cellulose triacetate (CTA), gas chromatography (GC), ionic liquids (IL), stationary phase