Preparation of attapulgite nanoparticles-based hybrid monolithic column with covalent bond for hydrophilic interaction liquid chromatography

In current study, an attapulgite nanoparticles-based hybrid monolith was prepared by crosslinking 3-trimethoxysilylpropyl methacrylate modified attapulgite nanoparticles with acrylamide and N, N′-methylenebisacrylamide. The crosslinking of attapulgite into the hybrid monolithic matrix has notable increased the column efficiency of adenosine comparing with the neat one without attapulgite. The resulting hybrid monoliths showed good permeability and good mechanical stability. It was further applied for separation of polar compounds by hydrophilic interaction chromatography (HILIC). The key factors affecting the separation efficiency of the developed hybrid monoliths (i.e. acetonitrile content, salt concentration and pH in the mobile phase) have been completely investigated. The column efficiency was up to 147,613 plates/m for the HILIC separation of aspirin. Good repeatability of retention time was achieved, with relative standard deviations for run-to-run (n = 3), column-to-column (n = 3) and batch-to-batch (n = 3) in the range of 1.08–1.45%, 2.44–3.41% and 2.15–4.96%, respectively. We propose that the attapulgite nanoparticles-based hybrid monolith would provide a promising stationary phase for hydrophilic interaction chromatography.