Graduate School of Pharmaceutical Sciences, Keio University, 1-5-14 Shibakoen, Minato, Tokyo 105-0011, Japan.
J Chromatogr B Analyt Technol Biomed Life Sci. 2010 Aug 15;878(24):2191-8. doi: 10.1016/j.jchromb.2010.06.026. Epub 2010 Jul 1.
For the development of well-defined highly dense thermo-responsive polymer grafted surface as an improved stationary phase for thermo-responsive chromatography, poly(N-isopropylacrylamide) (PIPAAm) brush-grafted porous polystyrene beads were prepared by surface-initiated atom transfer radical polymerization (ATRP). The PIPAAm grafted region of polystyrene beads was adjusted by the addition of isooctane as a poor solvent for polystyrene upon the reaction of ATRP initiator immobilization. Using a thermo-responsive HPLC column containing the prepared beads with PIPAAm brush grafted on the inside pores nearby the outer surfaces, angiotensin subtypes were effectively separated with aqueous mobile phase, because the densely grafted PIPAAm on nearby the outer surface effectively interacted with the peptides hydrophobically. Retention of basic peptide was achieved by the beads with basic mobile phase. These results indicated that the prepared beads with grafted PIPAAm nearby the outer surface became an effective chromatographic stationary phase for retaining basic peptides using wide pH range of mobile phase.
为了开发明确的高密热敏聚合物接枝表面，作为热敏色谱的改进固定相，通过表面引发原子转移自由基聚合（ATRP）制备了聚（N-异丙基丙烯酰胺）（PIPAAm）刷接枝多孔聚苯乙烯珠。通过在 ATRP 引发剂固定化反应中添加作为聚苯乙烯不良溶剂的异辛烷，调节聚苯乙烯珠上的 PIPAAm 接枝区域。使用含有在内外表面附近的内孔中接枝 PIPAAm 的刷状的热敏 HPLC 柱，用水性流动相有效地分离了血管紧张素亚型，因为在外表面附近密集接枝的 PIPAAm 有效地与肽疏水相互作用。通过具有碱性流动相的珠子实现了碱性肽的保留。这些结果表明，在内外表面附近接枝 PIPAAm 的珠粒成为使用宽 pH 范围流动相保留碱性肽的有效色谱固定相。
