The Study On Preparation And Computer Simulation Of Molecular Imprinted Polymers For Salbutamol

Salbutamol (SAL) is a selective β2-adrenoreceptor agonist which was extensively used in thetherapeutic of asthma. In addition, the drug can also promote the growth of muscle tissue andcarcass leanness, illegal traders were used in animal feed as additive. The residues of SAL in liverand meat can be harmful to human beings. In many countries, SAL has been banned for feedadditive, and the maximum residue limits of SAL in foods have been established to ensure foodsafety.Molecularly imprinted polymers (MIPs) are a new kind of tailor-made material, which hashigh affinity and selectivity for its template. It can be used for enrichment for determination of tracematerial. With the development of computer technology and the theory of quantum chemical study,computer simulation has been widely applied to molecular imprinting preparation. This paper usesdensity functional theory (DFT) for the theoretical research of SAL-MIPs, and experiment with theguide of simulation results. The main research contents are as follows:The DFT functions including the B3LYP, PBE, M062X, LC-WPBE, CAM-B3LYP, andWB97XD et al. were used to find the best method for geometry optimization of SAL in comparisonwith crystal data. The data showed that the LC-WPBE method was reliable in comparison with thecrystal data. Thus the molecular structure of SAL, MAA, and their subsequent complex wereoptimized using the LC-WPBE with6-31G(d, p) basis set. SAL was taken as a template molecule,and methacrylic acid (MAA), acrylamide (AM) and4-vinyl pyridine (4-VP) were taken as singlefunctional monomers. At the same time, MAA and AM were taken as hybrid functional monomers.Density functional theory (DFT) at the LC-WPBE/6-31G(d, p) level was used to investigate thegeometry configurations optimization, the action sites, the natural bond orbital (NBO) charges, thebinding energies of the imprinted molecule, and the solvation energy. The mechanism betweensalbutamol and different functional monomers were also discussed. The results showed that theinteraction between SAL and MAA is the strongest and the best ratio is1:4. The polymer with theratio of1:4(SAL-MAA) had the lowest binding energy (-194.117kJ/mol) and the maximum chargetransfer trend (0.257).The solvation energies of SAL-MIPs in different solvents (chloroform, ACN, toluene,methanol, and water) are discussed. The results showed that the SAL-MIPs which was synthesizedin chloroform had the better molecular recognition ability and absorbability. On the basis of calculation results, the theoretical predicted model of affinity and selectivity ofSAL-MIPs is established, which can commendably simulate the self-assembly of SAL-MIPs,polymerization, elution, and rebinding. The results showed that the SAL-MIPs had a better specificabsorption capacity to SAL.With the guide of calculation results, the SAL-MIPs were synthesized by the precipitationpolymerization approach. The type and quantity of solvent on the preparation of SAL-MIPs werediscussed. The static equilibrium adsorption method was used to study the adsorption capacity andselectivity properties of the MIPs. The experimental results showed that the SAL-MIPs synthesizedin ACN (40mL) had the best effect. The particle size of MIPs is about170nm and the NIPs is260nm. With the different concentration and imprint ratios, the adsorption capacity and selectivity ofMIPs were better than NIPs. Analysis of the Scatchard plot revealed that the binding sites of MIPsto SAL were unequal class under the studied concentration range, the dissociation constant (Kd) andapparent maximum adsorption quantity (Qmax) of SAL were Kd1=5.266mg/L, Qmax1=6.906mg/gand Kd2=177.620mg/L、Qmax2=27.432mg/g, respectively.Computer simulation is used to guide the synthesis condition of SAL-MIPs and improve theaffinity and selectivity. Applying quantum chemistry to optimize the molecular imprinting systemand explain the imprinting mechanism will provide a theoretical and experimental reference for thefurther study on SAL-MIPs. This study can provide theoretical and experimental references for theselective separation, enrichment, and detection of SAL in the complex matrix food.