Silica based click amino stationary phase for ion chromatography and hydrophilic interaction liquid chromatography

Abstract

A silica based amino stationary phase was prepared by immobilization of propargylamine on azide-silica via click chemistry. This readily prepared click amino stationary phase demonstrated good selectivity in separation of common inorganic anions under ion chromatography (IC) mode, and the triazole ring in combination with free amino group was observed to play a major role for separation of the anions examined. On the other hand, the stationary phase also showed good hydrophilic interaction liquid chromatography (HILIC) properties in the separation of polar compounds including nucleosides, organic acids and bases. The retention mechanism was found to match well the typical HILIC retention.

A hyperbranched polyethylenimine functionalized stationary phase for hydrophilic interaction liquid chromatography

“…The apparent anion exchange capacity was~1.26 meq/g calculated from elemental analysis data, while its effective capacity was measured to be~0.35 meq/column via the breakthrough method described previously [10].…”

“…Among them, amino SPs bear positive charges under HILIC conditions and thus prevail in the separation of negatively charged analytes [10,13]. In this case, the retention is dominated by ion exchange besides typical HILIC adsorption or partitioning mechanisms [10]. This in principle leads to higher selectivity relative to neutral SPs, especially for separation of cationic polar analytes.…”

“…), charged (e.g., amino [10] and arginine [11]), and zwitterionic [12]. Among them, amino SPs bear positive charges under HILIC conditions and thus prevail in the separation of negatively charged analytes [10,13]. In this case, the retention is dominated by ion exchange besides typical HILIC adsorption or partitioning mechanisms [10].…”

“…The majority of HILIC SPs are based on silica gel grafted with many kinds of functional groups, e.g., neutral (amide [8], polyvinyl alcohol [9], etc. ), charged (e.g., amino [10] and arginine [11]), and zwitterionic [12]. Among them, amino SPs bear positive charges under HILIC conditions and thus prevail in the separation of negatively charged analytes [10,13].…”

Novel imidazolium-embedded N,N-dimethylaminopropyl-functionalized silica-based stationary phase for hydrophilic interaction/reversed-phase mixed-mode chromatography

“…Since it could produce multiple interaction mechanisms between the stationary phases and analytes, complex samples with different characteristics could be efficiently separated via mixed-mode stationary phases. Recently, a variety of mixedmode stationary phases, including RPLC/anion-exchange chromatography [10][11][12][13][14], RPLC/cation-exchange chromatography [15], HILIC/anion-exchange chromatography [16][17][18], HILIC/cation-exchange chromatography [19], RPLC/NPLC/ anion-exchange chromatography [20], HILIC/RPLC/anionexchange chromatography [21,22], and HILIC/RPLC [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39], have been reported and further used for separation of both small molecules and macromolecules. For example, Sun et al [12] prepared benzimidazole modified silica-based stationary phase for RPLC/anion-exchange chromatography.…”