聚N-异丙基丙烯酰胺硅胶键合固定相的制备与评价

以3-巯丙基三甲氧基硅烷为偶联剂,将聚N-异丙基丙烯酰胺(PNIPAM)键合到硅胶上,制得了键合固定相（SI-PNIPAM）填料,并用元素分析、红外光谱等对其进行了表征。以甲醇-水为二元流动相,用多环芳烃、碱性物质对该固定相进行了色谱评价,并考察了该固定相的适用pH范围及水解稳定性。结果表明:该固定相具有较好的色谱性能与温敏特性,并且在pH 2.5～7.5时稳定性良好。

Preparation and characterization of poly(N-isopropylacryl-amide) bonded silica gel stationary phase

A thermal sensitive bonded stationary phase, poly (N-isopropylacrylamide) bonded silica gel stationary phase (SI-PNIPAM), was prepared by reacting silica gel with 3-mercaptopropyltrimethoxysilane (MPS). The characterization of the prepared packings was carried out with elemental analysis and Fourier transform infrared (FT-IR) spectroscopy. The chromatographic evaluations were carried out by testing with polycyclic aromatic hydrocarbons and basic compounds using methanol-water as a binary mobile phase. The applicable range of pH and stability of SI-PNIPAM were also evaluated. The results showed that the stationary phase has excellent chromatographic properties, thermal-responsibility and resistance to hydrolysis between pH 2.5 and 7.5. It can be used to separate basic solutes efficiently due to the existence of the special structure containing internal polar amide group contributing to restraining the activity of the residual silanol group below the lower-critical-solution temperature (LCST).