Synthesis and application of novel silver magnetic amino silicone adhesive particles for preparation of high purity α-linolenic acid from tree peony seed oil under applied magnetic field.

Silver magnetic amino silicone adhesive (Fe3O4@SiO2@NH2@Ag) particles were prepared for the purification of α-linolenic acid from tree peony seed oil under applied magnetic field. First, Fe3O4@SiO2@NH2@Ag particles were prepared and physicochemically characterized, including XRD, TG, FTIR, SEM, magnetic hysteresis curves and elemental analysis. The static process for the purification of α-linolenic acid using Fe3O4@SiO2@NH2@Ag particles was investigated, including adsorption curve, desorption curve, elution solvent composition and adsorption isotherm. The result indicated that 0-1-4% acetone-n-hexane elution solvent was selected for the gradient elution process, 2 h and 60 min were the time required to reach adsorption and desorption equilibrium, 20 °C was selected as the adsorption temperature, Langmuir model was suitable to fit and explain the equilibrium data, and the adsorption process was spontaneous and exothermic. Under applied magnetic field, the dynamic process for the purification of α-linolenic acid using Fe3O4@SiO2@NH2@Ag particles was investigated, and the optimum conditions were 20:1 µL/g loading amount, 0.5 mL/min flow rate and 51.73 Oe magnetic field intensity. After purification, the purity and recovery ratio of α-linolenic acid were calculated to be 94% and 74%, respectively. Furthermore, the recycled Fe3O4@SiO2@NH2@Ag particles still achieved better purification result. Therefore, the developed method shows a good application prospect in the field of separation and purification of α-linolenic acid.

Magnetically stabilized bed packed with synthesized magnetic silicone loaded with ionic liquid particles for efficient enrichment of flavonoids from tree peony petals.

In this work, synthesized magnetic silicone loaded with ionic liquid (Fe3O4@SiO2@IL) particles combined with gas-liquid-solid magnetically stabilized bed (GLS-MSB) were applied to enrich flavonoids from tree peony petal extraction solution. The magnetic core (Fe3O4) encased in silica was conducive to its rapid and efficient separation, and the modification of silica with ionic liquids (ILs) could provide the functional groups for selective adsorption of flavonoids. Furthermore, the magnetic materials were evenly dispersed in the GLS-MSB system, realizing the adequate contact and causing the positive influence on the result. After physicochemical characterization, the prepared Fe3O4@SiO2@IL (IL=VBimBr) particles were validated in the enrichment performance of flavonoids, including the type of ionic liquid loaded, desorption solution, adsorption and desorption kinetics. The adsorption kinetics obeyed the pseudo-second-order model, the adsorption isotherms were consistent with the Langmuir equation, and the adsorption process was spontaneous and exothermic. Additionally, the dynamic processes using GLS-MSB packed with Fe3O4@SiO2@IL particles were evaluated systematically, deriving the optimum conditions (5 mL/min liquid flow rate, 130 mL Loading amount and 42.55 Oe magnetic field intensity) and improving the purity of flavonoids. After enrichment, the Fe3O4@SiO2@IL particles were successfully recycled and reused. Overall, the developed method offers a great potential for the enrichment of flavonoids from natural materials.