Investigation of pi-pi and ion-dipole interactions on 1-allyl-3-butylimidazolium ionic liquid-modified silica stationary phase in reversed-phase liquid chromatography.
1-Allyl-3-butylimidazolium bromide ionic liquid [AyBIm]Br was prepared and used for the modification of mercaptopropyl-functionalized silica through surface radical chain-transfer addition. The obtained ionic liquid-modified silica (SiImBr) was characterized by elemental analysis, infrared spectroscopy, NMR spectroscopy, and thermogravimetric analysis. The selective retention behaviours of polycyclic aromatic hydrocarbons (PAHs) including some positional isomers were investigated using SiImBr as a stationary phase in reversed-phase liquid chromatography. The results showed that SiImBr presented multiple interactions including hydrophobic, pi-pi, and ion-dipole interactions during the separation of PAHs and dipolar compounds. However, it is proposed that pi-pi and ion-dipole interactions play important roles in the separation of PAHs and dipolar compounds. These results indicate that the ionic liquid-modified silica stationary phase is promising for future applications. A commercially available monomeric octadecylated silica (ODS) column and a custom-made poly(styrene)-grafted silica (Sil-St(n)) column were used as references.
Qiu
Hongdeng
H
Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan.
Takafuji
Makoto
M
Liu
Xia
X
Jiang
Shengxiang
S
Ihara
Hirotaka
H
D056148:Chromatography, Reverse-Phase / Q000379:methods*; D057927:Hydrophobic and Hydrophilic Interactions; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D016015:Logistic Models; D019906:Nuclear Magnetic Resonance, Biomolecular; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry* / Q000302:isolation & purification; D012822:Silicon Dioxide / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D013818:Thermogravimetry
D007093:Imidazoles; D052578:Ionic Liquids; D011084:Polycyclic Aromatic Hydrocarbons; D012822:Silicon Dioxide