Selective Adsorption Of Zinones Pesticides And Oxidation Degradation Efficiency Of 172 Nm Xenon Excimer Lamp

In this paper,new surface molecularly imprinted polymers with different materials as carriers were prepared in different optimized ratios using metal organic framework（NH₂-MIL-88B）,porous aromatic framework（PAF-6）,and covalent organic framework（COF-COOH）as support materials,and the adsorption performance and mechanism of the polymers were examined.The surface molecular imprinting technique was combined with the solid phase extraction（SPE）technique to investigate the performance parameters of the solid phase extraction column using three surface imprinted materials as the sorbent of the solid phase extraction column.These novel sample pretreatments were combined with high performance liquid chromatography-photo-diode array（HPLC-PDA）to establish a method for the detection of trace zinone pesticides in the aqueous environment,and the feasibility of the method was verified by determining method linearity,reusability,spiked recovery,actual sample detection,and comparison with commercial columns.Then,two systems,wet degradation and dry degradation,were used to degrade pymetrozine（PYM）,chloridazon（Ch）and metamitron（MET）,respectively,using a novel equipment 172 nm xenon excimer oxygen generator.The conditions in the optimization of the degradation process were explored,and the degradation process was explored and analyzed.It mainly includes the following four parts:1.NH₂-MIL-88B@MIPs were prepared by precipitation polymerization using the MOF material NH₂-MIL-88B as a carrier,chloridazon as a template molecule,and acrylamide as a functional monomer.The polymer adsorption rate was fast,reaching dynamic equilibrium at1 min,while the adsorption amount was 5.99μg mg^-1 at a concentration of 30μg m L^-1.In the selective adsorption experiment,the imprinting factors（IF）were 2.12,2.06 and 1.56 for structurally similar Ch,MET and PYM,respectively,and 1.05 and 1.11 for structurally dissimilar enrofloxacin and norfloxacin,respectively,with good selectivity for the zinone pesticides.The imprinted material was used as the packing material of the SPE column,and the parameters of the self-made column were optimized to obtain the optimal loading solvent（ethanol:water=10:90（V/V））,eluent（water）,elution solvent（100%methanol）,and elution volume（3 m L）,and the recovery of the column could still reach 102.18%after eight times of reuse.A new method for the detection of Ch was established by combining HPLC-PDA with SPE.The limit of detection（LOD）of the method in matrix was 2.94 ng m L^-1 and the limit of quantification（LOQ）was 9.80 ng m L^-1.The recoveries of the spiked recovery experiments at different concentrations were 77.13～102.4%with the relative standard deviations（RSD）in the range of 1.36%～5.15%.The self-made SPE column was applied to multiple water samples,and the developed method could be successfully used for the determination of chloridazon in the aqueous environment.2.The PAF-6 surface imprinted polymers（PAF-6@MIPs）were successfully prepared by the method of suspension polymerization,in which PAF-6 was the support material,N6-benzoylaadenine（the structural analogue of PYM）was used as the dummy template,andα-methacrylic acid was the functional monomer.The results of dynamic adsorption and adsorption isotherm showed that the adsorption equilibrium was reached within 8 min and the adsorption capacity was 7.40μg mg^-1 at 30μg m L^-1.In the selective adsorption experiment,the IF for N6-benzoyladenine,PYM,and MET with similar structures were 1.84,2.49,and2.25,respectively and the IF for enrofloxacin and tetracycline hydrochloride with different structures were 1.08 and 0.35,respectively.PAF-6@MIPs used as the column packing of the SPE.SPE column conditions were optimized,including washing,eluent,elution volume,etc.In the matrix,the LOD was 4.62 ng m L^-1,LOQ was 15.39 ng m L^-1 and the linearity was good in the range of 0.05 to 400μg m L^-1.The recovery rate of well water was 102.99%～108.31%,and the RSD was 1.39%～1.83%.In the experiment of treating actual water environment samples,the self-made column performed well.Using a C₁₈ column,a Florisil column,and self-made column for comparative experiment of sample solutions based on well water,the recovery rate of the sample could reach 100.14%after PAF-6@MIPs treatment.3.Surface molecularly imprinted polymers（COF-COOH@MIPs）were synthesized with the covalent organic framework COF-COOH as a carrier,6-（4-aminophenyl）-4,5-dihydro-5-methyl-3（2H）-pyridazinone as the dummy template for MET,andα-methacrylic acid as a functional monomer with the addition of crosslinker and initiator.The polymers reached adsorption equilibrium at 1 min,and the adsorption amount was 4.67μg mg^-1 when the sample solution concentration was 30μg m L^-1.The COF-COOH@MIPs were used as the packing material of the SPE column,and the parameters of the self-made column were optimized to obtain the optimal loading solvent（methanol:water=10:90（V/V））,eluent（water）,elution solvent（methanol:water=70:30（V/V））,and elution volume（1 m L）.Establishment of a SPE-HPLC-PDA method.The LOD of the established method in aqueous matrix was 2.94 ng m L^-1 and LOQ was 9.80 ng m L^-1 with good linearity in the range of 0.03～400μg m L^-1.The recoveries ranged from 100.94%to 102.82%with six cycles of the self-made SPE column under the optimized conditions.The spiked recovery experiments were performed on the actual water samples,and the obtained spiked recoveries ranged from 98.51%to 103.75%with the RSD lower than 2%.The developed method could be used for the determination of MET in the aqueous environment when multiple water samples were tested.All of the above showed that the COF-COOH@MIPs had good performance and provided a new pretreatment method for MET and other zinones in the aqueous environment.4.The degradation of Ch,PYM,and MET were studied using a novel device-the 172 nm xenon excimer oxygen generator.Using air as the gas source,the NO_x content in the gas product of the 172 nm xenon excimer oxygen generator was much lower than that produced by the commercially dielectric barrier discharges ozone generator,with a content of only 0.024%of the latter.Optimization of degradation conditions.The three pesticides had higher degradation efficiency at a reaction temperature of 20°C and degradation method of dry degradation（active oxygen）.Under the above conditions,when the degradation time was set to 60 min,the degradation rate of Ch was 54.53%;the degradation rate of PYM could reach98.95%,almost completely degraded;the structure of MET was similar to that of Ch,and the degradation effect was also close to that of Ch,with the degradation rate of 66.46%.