| Monolithic titania column has been become the new High performance liquid chromatography medium and drawing increasing attention in recent years, owing to that it is possessing the all advantages of monolithic column and great mechanical strength as well as excellent pH stability (pH=1-14). In addition, titania holds fascinating features of ligand-exchange with organo-phosphates, such as phospholipids, nucleotides, phosphopeptides or phosphoproteins and hardly adsorb the basic compounds irreversibly like silica materials, so that titania column has excellent prospect in the field of organo-phosphates analysis.The studies in this thesis included two aspects:(1) Monolithic titania materials with macro-mesoporosity bimodal texture have been prepared through a template-free sol-gel approach, based on the reaction of hydrolysis and polycondensation of titanium isopropoxide promoted by the slow released water from esterification between acetic acid and methanol under a strong acidic condition. With the coarsening of the titania oligomers, phase separation and sol-gel transition processes take place so as to form a homogeneous gel system that will change into a monolith after aging, drying and heat treatment. The synthesized titania monolith derived from the molar ratio of Titanium isopropoxide/Methnol/Acetic acid/Hydrochloric acid is 1/4/5/0.6, which possesses a specific surface area of 77 m2 g-1, an anatase crystallite structure and great mechanical strength after calcined at 350°C. The synthesis method applied here is simple and easy to implement as the hydrolysis of titanium isopropoxide is using the esterification-released water and no special chemical modifiers such as poly(ethylene oxide) (PEO) or formamide is needed to control the reaction process. The properties of biomodal porous structure, satisfactory surface area and high mechanical strength shows that the proposal synthesis method is good and satisfactory.(2) High performance liquid chromatography (HPLC) on titania column was performed for phosphatidylcholine (PC) separation and analysis. To fully understand the retention mechanism of PC on titania, the effect of mobile phase type, %acetonitrile (%ACN) in sample, phosphate buffer concentration, %ACN in eluent, buffer pH and ?ow rate were all studied. Separation depended on the eluent conditions and PC retention was attributed to the cooperation of hydrophilic interaction and ligand exchange. PC in soybean lecithin products was completely separated from other components within 6 min and quantitative analysis was achieved by an external standard method, with a correlation coefficient (R2) of 0.9947. The method precision and detection limit of PC were 3.40% and 0.2 mg, respectively, with the recovery ranging from 91% to 101%. Moreover, PC and glycerol monostearate standard mixture was successfully isolated by the proposed method, which underlined the selective affinity of titania for phosphorylated lipids. With the superiority of simplicity, rapidity and accuracy, this HPLC method based on titania is a competent method for the determination of PC in lecithin samples with prospects in the field of organo-phosphates analysis.
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