Preparation And Properties Of Magnetic Molecularly Imprinted Materials For Selective Adsorption Of Sulfamethoxazole

Sulfamethoxazole is a common antibiotic that is often used to treat diseases caused by bacteria and other microorganisms and is widely detected in natural waters and soil.It is pointed out that sulfonamides have certain toxicity to animals and plants in water and may induce gene variation.It can also accumulate in the food chain and eventually threaten human health,so it is necessary to establish an accurate and effective method for the detection of sulfamethoxazole.In this paper,molecular imprinting technology and magnetic solid phase extraction technology were combined to synthesize sulfamethoxazole molecularly imprinted polymer with high selective adsorption ability to target molecules by using sulfamethoxazole as template molecule.In addition,magnetic nano-Fe₃O₄ was used as the loading material,which was modified and coated with molecularly imprinted polymer,and the required magnetic molecularly imprinted materials（MMIPs）and magnetic non-imprinted materials（MNIPs）were finally prepared.The prepared MMIPs not only have selective adsorption holes for specific target objects,but also can be rapidly separated from the solution by external magnetic field.This paper determines the optimal conditions in the process of preparation of polymeric material and the optimal ratio of materials,the template molecule and functional monomer,crosslinking agent turnover ratio of 1:4:50,initiator dosing amount to 30 mg,solvent acetonitrile dosing amount to 30 ml,create the best MMIPs adsorption effect,and the MMIPs and MNIPs materials were characterized,mainly through the scanning electron microscope（SEM）,Fourier infrared spectrum（FTIR）to see the sample of synthetic conditions and microstructure.At the same time,the optimum conditions of adsorption and desorption were obtained.The kinetic and thermodynamic analysis of the adsorption results were carried out to determine the reaction type through the analysis of the fitting results,and the theoretical maximum adsorption capacity of MMIPs was calculated to be23.21mg/g.Finally,selective adsorption of MMIPs was studied in this study.Four kinds of substances and targets similar to sulfamethoxazole in structure or molecular weight,sulfadiazine,sulfadimidine and bisphenol A,were selected to form A unit,binary and multi-component system,so as to test the selective adsorption performance of MMIPs in the presence of interfering substances.Humic acid was taken as the representative of organic matter in water and sodium chloride as the representative of anion and anion in water.The results showed that the adsorption effect of MMIPs on the target was affected by different concentrations of interfering substances,but the effect was not significant.The recovery rate of sulfamethoxazole was75.97⁸8.74%and RSD was 4.3⁷.3%in the detection of actual water samples with two standard concentrations.