| Titania has been extensively applied in different fields such as catalysis, optics, andseparation science for its unique properties and it has attracted researchers great attention.Titania owns excellent chemical stability in pH1-14range as a chromatographic packingmaterial. The fatal defects including "irreversible adsorption" and "bad-tail" of alkalinecompounds on silica do not exist on titania. Titania is expected to play an important role inthe food safety and the life sciences. In this paper, monolithic titania materials wereprepared through a template-free sol-gel synthesis route and the synthesis conditions werealso studied. In the last, chromatographic separation of benzoic acid and nicotinic acidcompounds was successfully demonstrated by using prepared TiO2monolith.The four aspects are included in this paper as follows:（1） Titania monolith materials were prepared by a sol-gel synthesis route, via usingtitanium isopropoxide，acetylacetone，hydrochloric acid and water as titania source. Effectfactors on formation and performance of titania monolithic material were also studied, thebest ratio of ingredients was Ti/AcAc/HCl/H2O=1:0.4:0.5:6. Prepared titania monolithsafter aging, drying and heat treatment were more than10cm in length, the mean mesoporeof titania monoliths was10.5nm, and the surface area of titania monoliths was96.9m2/g,which was characterized by SEM and XRD analyses. The amide and carboxylatecompounds standards were analyzed with the synthesized titania monolithic column toevaluating the performance of titania monolithic column.（2）A rapid method for the determination of sour additive, citric acid in beverage byreverse-phase high performance liquid chromatography on titania was developed. Thechromatographic conditions were as follows: a Titania Sachtopore-RP column （250mm×4.6mm,5μm） as a separation column, a mixture of water and methanol at a volumeratio of60to40containing3mmol/L phosphate used as mobile phase, flow rate of0.8mL/min, column temperature60℃, and the detection wavelength210nm. The linear rangeof the method was0.02-8.0mg/mL with a detection limit of2.4μg/mL（3σ）. The recoverieswere between92.79%and99.30%. RSD （n=8） was less than0.72%. The accuracy andprecision of the proposed method can satisfy with the request to determine citric acid inbeverage samples and the method is simple, timesaving, and precise.（3）The compounds of benzoic acid and nicotinic acid were analyzed with synthesizedand activated titania monolithic column, buffer pH, buffer concentration, acetonitrilepercentage and flow rate were studied, the best chromatographic condition was determined,Meanwhile, the results are satisfactory, so it is applicable to the analysis of benzoic acid and nicotinic acid in several kinds of food samples. |
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