Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada.
Anal Chem. 2013 Jun 18;85(12):5684-91. doi: 10.1021/ac400350x. Epub 2013 Jun 7.
Stationary phases for hydrophilic interaction liquid chromatography (HILIC) are predominantly based on silica and polymer supports. We present porous graphitic carbon particles with covalently attached carboxylic acid groups (carboxylate-PGC) as a new HILIC stationary phase. PGC particles were modified by adsorbing the diazonium salt of 4-aminobenzoic acid onto the PGC, followed by reduction of the adsorbed salt with sodium borohydride. The newly developed carboxylate-PGC phase exhibits different selectivity than that of 35 HPLC columns, including bare silica, zwitterionic, amine, reversed, and unmodified PGC phases. Carboxylate-PGC is stable from pH 2.0 to 12.6, yielding reproducible retention even at pH 12.6. Characterization of the new phase is presented by X-ray photoelectron spectroscopy, thermogravimetry, zeta potentials, and elemental analysis. The chromatographic performance of carboxylate-PGC as a HILIC phase is illustrated by separations of carboxylic acids, nucleotides, phenols, and amino acids.
用于亲水相互作用液相色谱（HILIC）的固定相主要基于硅胶和聚合物载体。我们提出了带有共价键合的羧酸基团的多孔石墨化碳颗粒（羧酸酯-PGC）作为一种新的 HILIC 固定相。PGC 颗粒通过将 4-氨基苯甲酸的重氮盐吸附到 PGC 上来进行修饰，然后用硼氢化钠还原吸附的盐。新开发的羧酸酯-PGC 相表现出与 35 根 HPLC 柱不同的选择性，包括裸硅胶、两性离子、胺、反相和未改性的 PGC 相。羧酸酯-PGC 在 pH 2.0 至 12.6 之间稳定，即使在 pH 12.6 时也能产生可重现的保留。通过 X 射线光电子能谱、热重分析、动电电势和元素分析对新相进行了表征。羧酸酯-PGC 作为 HILIC 相的色谱性能通过羧酸、核苷酸、酚类和氨基酸的分离得到说明。
