Study On Preparation Technology Of Vc Palmitate

Experiment adopt the sulfric acid esterification method to prepar Vc palmitate，theeffects of stalling reaction time，reaction temperature，the molar ratio of Palmitic acid andVc，stirring reaction time，amount of sulfuric acid，and sulfuric acid concentration on theyield are particularly researched. And the techniqued conditions are optimized byorthogonal experimental design. And good techniques conditions and yield are received，the molar ratio of Palmitic acid and Vc is1.2，amount of sulfuric acid is25mL，thereaction temperature is28℃，the stalling reaction time is19h，the stirring reaction time is2h，and the yield of crude products is68.07%.In the choice of precipitation agent，we use a mixture of ice water and ethyl acetate，and study the effects of different ratio of ice water and ethyl acetate on the crude productprecipitated state，filtration，and the yield. This method avoid emulsification and gainbetter grain shape. It makes the crude products separation easily and the best volumeproportion of ice water and ethyl acetate is1:0.29.In order to slow down or inhibit the oxidation of Vc，we add antioxidant synergisticagent. from the experiment，we can obtaine the best synergistic effect is phytic acid，andthe suitable addition amount is1.75g，product yield finally reached71.31%，the3.24%higher than the original.In the purification process，we research the effects of the extraction temperature andthe volume ratio of toluene-water on the yield of products，and the effects of therecrystallisation of the blended liquor of hexane and ethanol on the yiled of products，andstudy on the best proportion of blended liquor of hexane and ethanol. The best purificationconditions and the yiled are obtained. Extraction temperature of toluene is8℃, Volumeratio is10:1, the best proportion of the blended liquor of hexane and ethanol is1:0.5，theyiled of products is74.26%.The products is tested by melting point，iodine titration，high performance liquidchromatography，infrared absorption spectrum, and the results indicated the content of Vcpalmitate in the self-made product is97.82%，the melting piont is109℃~114℃. Theproducts have good outward appearance and stable colour. The quality of products attainto the standards of GBl6314-1996.