A method for separating flavonoid substances in Camellia nitidissima Chi based on magnetic nanoparticle-PAMAM nano composites, comprising:
- preparing PAMAM dendrimer:
- performing Michael addition reaction between ethylenediamine and methyacrylate to obtain generation 0.5 polyamidoamine dendrimer, namely PAMAM G0.5;
- wherein the Michael addition reaction is performed under 25° C.;
- reacting the obtained PAMAM G0.5 with excessive ethylenediamine under 25° C. to obtain generation 1.0 polyamidoamine dendrimer, namely PAMAM G1.0;
- repeating the above two steps to obtain PAMAM with different generation;
- preparing magnetic nanoparticle-PAMAM nano composites
- dispersing magnetic nanoparticles into methanol through magnetic separation to obtain methanol solution with 0.0128 mol/L concentration;
- diluting 25 mL methanol solution containing magnetic nanoparticles therein to 150 mL by methanol and performing ultrasonication for 30 min;
- adding 10 mL 3-aminopropyltriethoxysilane, stirring and performing ultrasonication for 7 hours;
- performing magnetic separation on the obtained solution after washing it by methanol for 5 times;
- dispersing the washed solution in methanol to obtain 5 wt % magnetic nanoparticle methanol solution;
- adding 200 mL methanol solution with methyacrylate into 50 mL 5 wt % magnetic nanoparticle methanol solution to obtain a mixed solution, wherein a volume concentration of the methyacrylate is 20%;
- performing ultrasonication to the mixed solution for 7 hrs in water bath at room temperature;
- collecting magnetic nanoparticles by magnet and washing it for 5 times by methanol and performing magnetic separation;
- adding 40 mL methanol solution with ethylenediamine, the volume concentration of the ethylenediamine is 20%, performing ultrasonication for 3 hrs at room temperature;
- washing the magnetic nanoparticles for 5 times with methanol and performing magnetic separation;
- repeatedly adding the methanol solution with methyacrylate and methanol solution with ethylenediamine;
- obtaining higher generations of magnetic nanoparticles modified by dendrimer for each cycle;
- washing the solution after cycle with 25 mL methanol for 3 times and washing with 25 mL water for 5 times;
- and obtaining the magnetic nanoparticles modified by PAMAM dendrimer by magnetic separation;
- and
- extracting and performing magnetic separation on the flavonoid substances in Camellia nitidissima Chi:
- adding the obtained magnetic nanoparticle-PAMAM nano composites in a Camellia nitidissima Chi extract;
- extracting for 0.5-3 hrs under ultrasound or microwave condition;
- separating the nanoparticle-PAMAM nano composites adsorbed and extracted with flavonoid substances through magnetic separation after the extraction, the flavonoid substances adsorbed by magnetic nanoparticles are extracted and separated by using an organic solvent from separated nanoparticle-PAMAM nano composites.