Preparation Of Molecular Imprinting Material Based On Silica And Their Application In A Solid-phase Dispersion Extraction Matrix For Methyl Parathion And Heavy Metal

Applying molecular imprinting techniques we prepared a hybrid organic-inorganic surface imprinted silica nanoparticles for specific recognition of methyl parathion.Using amino modified silica nanoparticles as supports,acrylamide as the functional monomer,y-methacryloxypropyl trimethoxy silane as the grafting agent,and methyl parathion as a template,we molecularly imprinted silica nanoparticles in in chloroform.The amino propyl functional monomer can not only direct the polymerization on silicon surface,it can also be used as an assistive monomer to drive the template agent into the shell structure to produce effective specific recognition sites.The resulting MIPs-SiO2 nanoparticles display three-dimensional core-shell architectures and large surface areas.-The molecularly imprinted polymars shell provides recognition sites for methyl parathion.Using MIPs-SiO2 nanoparticles as sorbents of solid-phase dispersion extraction,trace amounts of methyl parathion are selectivity extracted from green vegetable and pear samples while eliminating matrix interferences,attaining recoveries of 84.7-94.4%for the samples.Combining the advantages of MCM-41 mesoporous materials and molecularly imprinted polymers,we designed and synthesized periodic Cd2+ imprinted mesoporous silica(CIMS)through a one-step hydrothermal process.Bifunctional ligand monomers[3-(c-aminoethylamino)-propyltrimethoxysilane]and template ions(Cd2+)were immobilized in the hexagonal channel walls of MCM-41,prior to polymerization.The resultant Cd-IMS revealed a highly ordered hexagonal structure,nano-sized pore diameters and wall thicknesses,and a large surface area.In addition,this material revealed good binding properties,including a large adsorption capacity(saturation adsorption capacity of 40 mg/g),highly specific recognition ability(maximum imprinting factor of 3.0),and rapid adsorption kinetics(equilibration within 5 min).Selectivity coefficients[KCIMS(Cd2+)/KCIMS(Cu2+ or Pb2+)]of the CIMS material demonstrated values of up to 2.29 and 3.08,respectively.Following six cycles of Cd2+ adsorption,the recovery of CIMS remained stable at around 89.3%,proving its recycling potential.Furthermore,CIMS was successfully applied to selectively separate and remove Cd2+ from mineral wastewater samples,with high Cd2+ recovery rates.This suggests that the routine recovery of Cd2+ from wastewater may be realized in an economically viable manner.