Molecularly imprinted microspheres (MIMs) were prepared using 4-aminopyridine (4-AP) as template molecule by aqueous microsuspension polymerization. The MIMs were packed into stainless steel column (250×4.6 mm I....Molecularly imprinted microspheres (MIMs) were prepared using 4-aminopyridine (4-AP) as template molecule by aqueous microsuspension polymerization. The MIMs were packed into stainless steel column (250×4.6 mm I.D.) for selective separation of 4-aminopyridine (4-AP) and 2-aminopyridine (2-AP). The influences of pH, kinds and concentration (c) of buffer on capacity factors were investigated in detail. The relationships of capacity factor (k′) with pH and concentration of buffer are quantitatively described firstly. The effects of pH of phosphate and acetate buffer on capacity factors are very different. The relationship between k′ and pH can be described by the following equation: k′=-8.23 + 9.23 pH-0.99 pH 2 (in phosphate buffer) with R 2=0.9775 and k′=6.79-3.76 pH + 0.68 pH 2 (in acetate buffer) with R 2=0.9866. Furthermore, the capacity factors were also greatly affected by the concentration of acetate buffer in mobile phase while non-imprinted molecule is poorly changed. It increases with decreasing the concentration of buffer-especially in low concentration buffer (c acetate<0.02 mol/L, final concentration in mobile phase). The fit curve of log k′ to log c is described by equation: log k′=-0.571-1.256×log c-0.186×(log c) 2 with R 2=0.9979. The ratio of acetate buffer to methanol was investigated and the optimal ratio for separation of 4-AP and 2-AP is below 1∶7.5 (V/V).展开更多
Molecularly imprinted microspheres (MIMs) of D-mandelic acid were synthesized in this study. Chloromethylated polystyrene beads modified with iniferter were used as supports for photo-grafting of a molecularly imprint...Molecularly imprinted microspheres (MIMs) of D-mandelic acid were synthesized in this study. Chloromethylated polystyrene beads modified with iniferter were used as supports for photo-grafting of a molecularly imprinted polymer (MIP) layer. The polymers were characterized by FT-IR, elemental analysis and thermo-gravimetric analysis to testify the polymer formation and its thermal stability. Scan- ning electron micrographs (SEM) show that the MIP particles are mono-dispersed and well-spherical, with the average diameter of 4.38 μm and size distribution coefficient of 1.02. Furthermore, the MIMs were packed in a stainless steel column and evaluated as stationary phases in high performance liquid chro- matography (HPLC). The prepared MIP exhibited a considerable capability of chiral separation between template and its enantiomer. Accordingly, this kind of MIP is likely to have wide applications in chemical sensing, chromatographic analysis and solid phase extraction.展开更多
文摘Molecularly imprinted microspheres (MIMs) were prepared using 4-aminopyridine (4-AP) as template molecule by aqueous microsuspension polymerization. The MIMs were packed into stainless steel column (250×4.6 mm I.D.) for selective separation of 4-aminopyridine (4-AP) and 2-aminopyridine (2-AP). The influences of pH, kinds and concentration (c) of buffer on capacity factors were investigated in detail. The relationships of capacity factor (k′) with pH and concentration of buffer are quantitatively described firstly. The effects of pH of phosphate and acetate buffer on capacity factors are very different. The relationship between k′ and pH can be described by the following equation: k′=-8.23 + 9.23 pH-0.99 pH 2 (in phosphate buffer) with R 2=0.9775 and k′=6.79-3.76 pH + 0.68 pH 2 (in acetate buffer) with R 2=0.9866. Furthermore, the capacity factors were also greatly affected by the concentration of acetate buffer in mobile phase while non-imprinted molecule is poorly changed. It increases with decreasing the concentration of buffer-especially in low concentration buffer (c acetate<0.02 mol/L, final concentration in mobile phase). The fit curve of log k′ to log c is described by equation: log k′=-0.571-1.256×log c-0.186×(log c) 2 with R 2=0.9979. The ratio of acetate buffer to methanol was investigated and the optimal ratio for separation of 4-AP and 2-AP is below 1∶7.5 (V/V).
基金This work was supported by the National Natural Science Foundation of China(Grant No.60121101).
文摘Molecularly imprinted microspheres (MIMs) of D-mandelic acid were synthesized in this study. Chloromethylated polystyrene beads modified with iniferter were used as supports for photo-grafting of a molecularly imprinted polymer (MIP) layer. The polymers were characterized by FT-IR, elemental analysis and thermo-gravimetric analysis to testify the polymer formation and its thermal stability. Scan- ning electron micrographs (SEM) show that the MIP particles are mono-dispersed and well-spherical, with the average diameter of 4.38 μm and size distribution coefficient of 1.02. Furthermore, the MIMs were packed in a stainless steel column and evaluated as stationary phases in high performance liquid chro- matography (HPLC). The prepared MIP exhibited a considerable capability of chiral separation between template and its enantiomer. Accordingly, this kind of MIP is likely to have wide applications in chemical sensing, chromatographic analysis and solid phase extraction.
