High temperature and highly selective stationary phases of ionic liquid bonded polysiloxanes for gas chromatography

摘要

Due to the special performance of " dual nature" and synthetic flexibility, ionic liquids (ILs) have been an attractive research subject of stationary phases for gas chromatography (GC). In this work, a novel ionic liquid (IL) bonded polysiloxane ([PSOMIM][NTf_2]) with anion of bis-trifluoromethanesulfonylimide (NTf_2-) was synthesized, and another one with chloride anion ([PSOMIM][Cl]) was also prepared for the purpose of comparison. The thermo-stability of the product was evaluated by thermogravimetric (TG) test and the result indicated that [PSOMIM][NTf_2] did not decompose slightly until 380°C. Then the solvation behaviors of the ILs were characterized using solvation parameter model. Subsequently, [PSOMIM][NTf_2] and [PSOMIM][Cl] were used as stationary phases to prepare capillary columns for GC, respectively. The column efficiency of [PSOMIM][NTf_2] column was 4776plates/m (k=3.64±0.08, naphthalene), and that of the other one was 3170plates/m (k=2.84±0.11, naphthalene). The selectivity of the novel stationary phases for analytes, including Grob reagent, aromatic positional isomers was further evaluated. Furthermore, the chromatograms of n-alkanes and polycyclic aromatic hydrocarbons (PAHs) on [PSOMIM][NTf_2] column were compared with that on [PSOMIM][Cl] column. [PSOMIM][NTf_2] stationary phase also exerted good selectivity for fatty acid methyl esters (FAMEs), polychlorinated biphenyls (PCBs) and aromatic amines.