Synthesis and caracterisation of new mixed-mode statinary phases

Chromatographic stationary phase is the core of high-performance liquid chromatography (HPLC) system. There into, the development of novel stationary phases with high separation efficiency and excellent selectivity has always been the focus of the study. Mixed-mode stationary phases have been proved to be with the merits of high separation selectivity, remarkably high loading capacity, and high separation efficiency. These stationary phases are classified based on the HPLC modes, emphasizing the preparation methods and further applications.In this work, two novel multifunctional stationary phases based on silica gel was synthesised starting from L-isoleucine. L-isoleucine was reacted with 4-phenylbutylamine and 3-aminoacetacilide to optain boc-Ile-PBA and boc-Ile-AA. Deprorection of these compounds gave Ile-PBA and Ile-AA. These compounds were reacted with dimethyloxalate to optain Ile-PBA-DMO and Ile-AA-DMO. Following by Ile-PBA-DMO and Ile-AA-DMO were reacted with 3-aminopropyltrimethoxysilane, reacted with spherical silica gel (5μm-60Å) gave Ile-PBA-Mix and Ile-AA-Mi stationary phases. The prepared stationary phases were characterized by elemental analysis, infrared spectroscopy (IR), scanning electron microscopy (SEM), Brunauer Emmett and Teller (BET) and solid-state 13C nuclear magnetic resonance (NMR). The prepared stationary phases were filled into empty HPLC column (250x4.6 mm) to optaind two different HPLC columns. Some chromatographic properties of these new columns were given as tabulated form.