Study On Separation Of Ophiopogon Japonicus Polysaccharide By Fe₃O₄/PSF Magnetic Composite Ultrafiltration Membrane

As drying Ophiopogon to raw material,extraction of polysaccharides was summarized by law-based Sevage.Polysaccharides extract was ultrafiltered with 50000 MWCO polysulfone as ultrafiltration membrane under room temperature, then the molecular weight of polysaccharides in the 50000 following extract(the content of 91.68%) was got.The proportion of the molecular weight of the total sugar between 30000 and 50000 was 53.6% and the proportion of'the molecular weight of the total sugar below 10000 was 29.6%.Magnetic composite ultrafiltration membraneâ… ,â…¡andâ…¢whose membrane matrix were polysulfone ultrafiltration membrane(30000,40000 and 50000)were obtained by in-situ method,their membrane MWCO range of variation were serial 7000-24000,9000-33000 and 15000-39000 without and under magnetic field.Magnetic composite ultrafiltration membraneâ…¡was selected.Polysaccharides extract was ultrafiltered when magnetic field strength and ultrafiltration pressure were changed.The proportion of ophiopogon japonicus polysaccharide whose molecular weight were between 30000 and 50000 and below 10000 in each sample were assessed,and optimized the process conditions of the fractionation of polysaccharides by magnetic composite membrane with single factor and orthogonal tests:ophiopogon whose molecular weight was between 30000 and 50000 was obtained in fluid retention when magnetic field strength and pressure regulator were 0.1T and 0.4MPa,ophiopogon whose molecular weight was below 10000 was obtained in through liquid when magnetic field strength and pressure regulator were 0.8T and 0.5MPa.Polysaccharides extract was continuous separated with magnetic composite membrane when the magnetic field strength and pressure were (0.1T,0.4MPa) and(0.8T,0.5MPa),then two samples A and D were determined with HPGPC,The analysis of GPC:the sample A, Mw was 39773,Mw/Mn was 1.51,the sample D, Mw was 8664,Mw/Mn was 1.42,The content of polysaccharides whose molecular weight were between 30000 and 50000 in the sample A and below 10000 in the sample D were 85.6% and 88.7% from the molecular weight distribution curves cumulative.To sum up, by changing the pressure and magnetic field strength, polysaccharides extract was better selective continuous separated by molecular weight when only a magnetic membrane was applied...