Indirect Hydrolytic Synthesis Of Titania Monolithic Column And Its Application In Separation Of Nicotinamide And Folic Acid

Monolithic titania column has both great mechanical strength and pH stability, solvingirreversible adsorption of silica to alkaline substances and "the silica matrix effect", so that it isgreatly concerned as new chromatographic materials.The studies in this thesis included these aspects:（1） With macro-mesoporosity bimodal texture, monolithic titania materials have beenprepared by a sol-gel method. The reaction of hydrolysis and polycondensation of titaniumisopropoxide promoted by the slow released water from esterification of methanol and aceticacid and methanol, and based on intervention of ethylene oxide （PEO）. The synthesized titaniamonolith which is good and satisfactory derived from the molar ratio of Titaniumisopropoxide/Methnol/Acetic acid/Hydrochloric acid is1/4/5/0.5and PEO is0.07g, whichpossesses a specific surface area of87.44m²g^-1, a satisfactory surface area, a length more than12cm, a high mechanical strengtha properties of biomodal porous structure and an anatasecrystallite structure after calcined at400℃.（2）A method for the determination of folic acid by high performance liquid chromatographyon titania in diet coke was reported in this thesis. The drink samples were separated with aTitania Sachtopore-NP column （250×4.6mm,5μm）. The chromatographic separation conditionswere: the mobile phase was pure water and methanol in the ratio of70to30, phosphate was20mmol/L, column temperature was60℃, with a flow rate of0.9mL/min. The detectionwavelength was280nm. The linear range of the method was5-25μg/ml with a detection limit of1.9220μg/ml. The recoveries of the method were between92.7%and95.1%. The relativestandard deviation of the method was less than0.68%. The method is simple, timesaving,accurate and precise and it is applicable to the determination of folic acid.（3） A method for the determination of nicotinamide in foods by titania-based highperformance liquid chromatography has been reported. The samples were separated with atitania-based column （250×4.6mm,5μm）. The chromatographic separation conditions were asfollows: a mixture of water and methanol in the ratio of90to10containing0.5mmol/L phosphate used as mobile phase, flow rate of0.8mL/min, column temperature70℃, and thedetection wavelength270nm. The linear range of the method was5-50μg/mL with a detectionlimit of1.42μg/mL. The recoveries were between92.56%and110.57%. RSD （n=8） was lessthan0.59%. The method is simple, reliable and accurate, and can be applied to the qualitycontrol of the nicotinamine drink.