Molecular-shape selectivity tuned by donor-acceptor type copolymers as organic phase in reversed-phase high-performance liquid chromatography.
The copolymer with a terminal reactive group (copoly-VP17MA12) was newly designed and prepared by selecting 4-vinylpyridine (VP) as an electron-donating monomer and methyl acrylate (MA) as an electron-accepting monomer. Copoly-VP17MA12 was grafted onto porous silica particles by a silanol coupling reaction with the terminal group. Individually, poly-VP15 and poly-MA20 with a terminal reactive group were also synthesized and co-grafted onto silica (Sil-cograft-VP17MA12) to compare the effect of the copolymer-grafted (Sil-copoly-VP17MA12) and polymer co-grafted stationary phases in HPLC separation. All the polymers were characterized by 1H NMR and FT-IR analysis before grafting on silica. Polymer grafting was confirmed by diffuse reflectance infrared Fourier transform (DRIFT), elemental analysis and thermogravimetric analysis (TGA). The intra- and intermolecular interaction between monomer units in copolymer-grafted and polymer co-grafted systems, respectively was observed by DRIFT measurement. The detailed chromatographic study revealed using PAHs as solutes that remarkably higher selectivity for planar/non-planar discrimination was observed with the copolymer-grafted phase than with the co-grafted stationary phase. In this paper, it is also discussed that the selectivity enhancement by copolymer-grafting in the Sil-copoly-VP17MA12 phase can be brought through intramolecular interaction between VP and MA.
Mallik
Abul K
AK
Department of Applied Chemistry and Biochemistry, Faculty of Engineering, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan.
Takafuji
Makoto
M
Ihara
Hirotaka
H
D000179:Acrylates / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods*; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry / Q000302:isolation & purification; D011108:Polymers / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry
D000179:Acrylates; D011084:Polycyclic Aromatic Hydrocarbons; D011108:Polymers; D011725:Pyridines; D012822:Silicon Dioxide; C029351:4-vinylpyridine; C035956:methyl acrylate