A carboxy precursor monolithic column, namely poly(carboxy ethyl acrylate-co-ethylene glycol dimethacrylate) was first produced in a 100 μm i.d. fused-silica capillary and subsequently surface bonded with n-octadecyl (C₁₈) ligands by a post-polymerization functionalization process with octadecylamine in the presence of N,N´-dicyclohexylcarbodiimide. The bonding of octadecyl ligands was achieved via an amide linkage between the carboxy functions of the precursor monolith and the amino group of the octadecylamine compound. The resulting C₁₈ monolith exhibited a very low electroosmotic flow (EOF), a fact that required the incorporation of small amounts of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) in the polymerization solution to produce a precursor monolith with fixed negative charges of sulfonate groups. This may indicate that the conjugation of the carboxy functions with octadecylamine occurred to a large extent so that the amount of residual carboxy functions was sparsely dispersed and not enough to produce a desirable EOF. The EOF velocity of the C₁₈ column having fixed negative charges provided by the incorporated AMPS increased with increasing ACN content of the mobile phase signaling an increased binding of mobile phase ions to the polar amide linkages near the monolithic surface, and a decreased viscosity of the mobile phase, both of which would result in increased EOF velocity. The C₁₈ monolithic column constituted a novel nonpolar sorbent for reversed-phase capillary electrochromatography for nonpolar solutes, e.g., alkylbenzenes, alkylphenyl ketones, and polyaromatic hydrocarbons, and slightly polar compounds including phenol and chlorophenols. The C₁₈ monolithic column exhibited relatively high selectivity toward chlorophenols differing by one chloro substituent.

中文翻译：

---

用于反相毛细管电色谱的具有键合十八烷基配体的聚（丙烯酸羧乙酯-共聚乙二醇二甲基丙烯酸酯）前体整体料

首先在 100 μm id 熔融石英毛细管中制备羧基前体整体柱，即聚（丙烯酸羧基乙酯-共聚乙二醇二甲基丙烯酸酯），随后通过聚合后官能化与正十八烷基 (C _{18 ) 配体进行表面键合在}N,N'-二环己基碳二亚胺存在下与十八烷胺进行工艺。十八烷基配体的键合是通过前体整体的羧基官能团和十八烷基胺化合物的氨基之间的酰胺键来实现的。生成的 C ₁₈整体材料表现出非常低的电渗流 (EOF)，这一事实需要在聚合溶液中加入少量 2-丙烯酰胺基-2-甲基丙烷磺酸 (AMPS) 以产生具有固定的磺酸基负电荷的前体整体材料。这可能表明羧基官能团与十八烷基胺的共轭在很大程度上发生了，因此残余羧基官能团的量分散得很稀疏，不足以产生所需的 EOF。_{C 18}的 EOF 速度具有固定负电荷的色谱柱由掺入的 AMPS 提供，随着流动相中乙腈含量的增加而增加，这表明流动相离子与整体表面附近的极性酰胺键的结合增加，以及流动相的粘度降低，这两者都会导致EOF速度增加。C ₁₈整体柱构成了一种用于反相毛细管电色谱的新型非极性吸附剂，用于分析非极性溶质，例如烷基苯、烷基苯基酮和多环芳烃，以及包括苯酚和氯酚在内的弱极性化合物。C ₁₈整体柱对不同氯取代基的氯酚表现出相对高的选择性。