Department of Chemistry and Chemical Engineering, Inha University, Incheon, Korea.
J Sep Sci. 2018 Sep;41(17):3372-3381. doi: 10.1002/jssc.201800329. Epub 2018 Jul 23.
A hydrophobic ionic liquid modified thermoresponsive molecularly imprinted monolith was synthesized using N-isopropylacrylamide as a thermoresponsive monomer and a long-chain hydrophobic ionic liquid as an auxiliary modification monomer. The ionic-liquid-modified thermoresponsive molecularly imprinted polymer was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. When the column temperature was 50°C, the synthesized monolithic column was successfully applied to the selective separation of homologue tanshinones within 7 min and eluted only by water (mobile phase) (theoretical plates more than 1.00 × 10 per meter). The negative Gibbs free energy (≤-2.37) values showed that the transfer of the tanshinones from the mobile phase to the stationary phase on this monolithic column was a thermodynamically spontaneous process. Good linearity of the five tanshinones by thermoresponsive monolith was obtained in the range of 0.100-25.0 μg/mL. The limit of detection (S/N = 3) and limit of quantitation (S/N = 10) were less than 0.0390 and 0.0630 μg/mL, respectively, with a relative standard deviation of <4.8%. In this proposed thermoresponsive chromatography method, the separation of homologue analytes can be achieved by changing the column temperature, and the use of water as the mobile phase would decrease the economic cost and organic pollution.
一种疏水离子液体改性的温敏分子印迹整体柱是通过 N-异丙基丙烯酰胺作为温敏单体和长链疏水离子液体作为辅助修饰单体合成的。离子液体改性的温敏分子印迹聚合物通过扫描电子显微镜和傅里叶变换红外光谱进行了表征。当柱温为 50°C 时，成功地在 7 min 内将合成的整体柱应用于同系物丹参酮的选择性分离，仅用水（流动相）洗脱（理论塔板数超过每米 1.00×10）。负的吉布斯自由能（≤-2.37）值表明，丹参酮从流动相转移到整体柱固定相是一个热力学自发过程。在该温敏整体柱上，五种丹参酮具有良好的线性关系，在 0.100-25.0 μg/mL 范围内。五种丹参酮的检测限（S/N=3）和定量限（S/N=10）分别小于 0.0390 和 0.0630 μg/mL，相对标准偏差小于 4.8%。在提出的温敏色谱方法中，可以通过改变柱温实现同系物分析物的分离，并且使用水作为流动相可以降低经济成本和有机污染。
