Preparation And Application Of Macroporous Silica And Investigation Of Core-Shell Chromatographic Packing Material

As highly efficient analysis and separation technique,high performance liquid chromatography(HPLC)has been widely used in all fields of society.Chromatographic packing material plays an important part in chromatography and has attracted much attention.Macroporous silica holds advantages in reducing mass transfer resistance because of its large pore size.In this paper,calcining the silica mixed with salt is the simple and rapid method of preparing macroporous silica and then applied in HPLC.First of all,the silica gel mixed with NaCl and LiCl,was calcinated in the muffle furnace.Then it was washed with deionized water to remove salt and macroporous silica gel was obtained.The temperature and time of calcination would have a great effect on the pore size and specific surface area.With proper control of temperature and time,macroporous silica gel could be obtained with different pore sizes.The difference of separation on chiral stationary phase(CSP)with different pore sizes and Van Deemter equation indicated that macroporous silica gel could decrease the mass transfer resistance.Then,Ketorolac could be well separated on the polysaccharide-based CSP coated on macroporous silica gel.The best resolution was obtained on OJ-H in the mobile phase of MeOH/FA(100/0.1)with the value of a and RS reaching 2.43 and 9.04 respectively.The composition of mobile phase,temperature and coating amount would affect the chiral resolution of Ketorolac.CSP with high coating amount could improve the efficiency of chiral preparation.Finally,with mercaptopropyltrimethoxysilane(MPTS)as single silicon source,thiol-nanoparticle was prepared.Triethylamine,concentration of surfactants and temperature would have great impact on the particle size.Then,core-shell macroporous silica was prepared with "Spheres-On-Sphere" method.The thiol-ene click chemistry was adopted to bind the chiral molecules,and applied in chiral separation.