Preparation Of Carbon Nanomaterial Hybrid Monolithic Column For Enrichment And Purification Of ?-sitosterol

?-Sitosterol is one of the main components of plant sterols,and it's widely found in various vegetable oil,nuts and some botanicals in nature.?-Sitosterol has many activities of lower serum cholesterol,anti-inflammatory and tumor-preventing and so on.Vegetable oil contains abundant ?-sitosterol,but the composition of vegetable oil samples is complex which would affect the separation and analysis of ?-sitosterol.Therefore,the purification and enrichment of test component before analysis is inevitable.Because of its advantages of simple preparation,high throughput analysis and good reproducibility,solid phase extraction(SPE)has become one of the most commonly used sample pretreatment technologies.In this paper,two kinds of monolithic columns were successfully prepared by redox method for the on-line analysis and purification of ?-sitosterol in vegetable oil.Firstly,poly(GO-co-C8-TEGDMA)monolithic column was prepared using 1-octene(C8)as monomer,triethylene glycol dimethacrylate(TEGDMA)as cross-linking agent,1-dodecanol and n-propanol as porogen,dibenzoyl peroxide(BPO)and N,N-dimethyl aniline(DMA)as initiators,in which graphene oxide(GO)was embedded.The monolithic column prepared above was characterized by scanning electron microscopy(SEM)and nitrogen adsorption-desorption measurement(BET).Then it was used as solid phase to enrich ?-sitosterol.After being coupled to C18 column,?-sitosterol adsorbed on the monolith was eluted and was analysed.Compared with the monolithic column without grapheme oxide,monolithic column prepared above had higher adsorption capacity of ?-sitosterol.Besides,the method has better repeatability and recovery.Secondly,the poly(ND-co-C12-co-TEGDMA-co-TAIC)was prepared using nanodiamond and 1-dodecene(C12)as co-monomer,TEGDMA and triallyl isocyanurate(TAIC)as cross-linking agent,methonal,n-hexyl alcohol and dimethylbenzene as porogen,BPO and DMA as redox initiators.?-Sitosterol from different vegetable oil samples was on line enriched and analysed successfully.The results showed that the addition of nanodiamond was beneficial to improving the structure of the monolithic column and increasing the adsorption capacity.