Application Of Surface Imprinting-solid Surface Fluorescence Technology In The Environment

At present,food safety problem is more and more widely concerned by the society.It plays an important role in people's health,rapid economic development,and national and social stability.The illegal use of food additives and the abuse of antibiotics have seriously jeopardized human health.Due to the complex operation of traditional detection methods and the long time of sample pretreatment,it is necessary to establish a rapid detection method for food additives and antibiotics.In this paper,surface molecularly imprinted polymers?SMIPs?are used to identify imprinted molecules with specific structure and size,and have high adsorption capacity.Moreover,solid surface fluorescence spectrometry has the advantages of simple,rapid,high sensitivity and direct determination of solid samples.An analytical method for rapid detection of rhodamine B?RhB?in food and sulfamethoxazole?SMZ?in the environment was developed based on surface imprinting and solid surface fluorescence.The main research contents are as follows:?1?Study on RhB-SMIPs-PVA substrate detection in RhBIn this study,RhB-SMIPs were prepared using SiO₂ as the carrier,MAA as the functional monomer,EGDMA as the crosslinking agent,acetonitrile as the pore forming agent,2,2'-azodiisobutyronitrile?AIBN?as the initiator.Then,the polymer powder was embedded in polyvinyl alcohol?PVA?Gel.The RhB-SMIPs-PVA were obtained by optimizing the PVA and gelatin mass fraction,solution ratio and powder addition amount.Finally,the gel substrate was used for fluorescence detection after enrichment.The results showed that the optimal conditions for the preparation of RhB-SMIPs-PVA were as follows:RhB-SMIPs powder was added at 0.05 g/mL?PVA?,the ratio of PVA with 6%mass fraction and sodium tetraborate with 4%mass fraction was 5?2.At the excitation wavelength of 500nm,the detection limit of this substrate against RhB can reach 0.1 mg/L.The substrate was adsorbed on RhB and Rh6G at the same time with the substrate without RhB-SMIPs powder.The enhancement factors of RhB-SMIPs-PVA substrate were 3.32 and 0.79 respectively at the concentrations of RhB and Rh6G at 80 mg/L.In the anti-interference experiments,the enhancement factor of RhB,sunset yellow,Sudan?and Sudan?were 2.95,1.08,1.06 and 0.68,respectively.Based on the establishment of the above method,RhB in chili powder,prune and sausage was tested.The results show that the minimum detection limit of RhB in solid phase samples can reach 0.5 mg/kg.?2?Study on RhB-SMIPs-Gel substrate detection in RhBIn this chapter,RhB-SMIPs powder prepared by SMIP technology was embedded in gelatin/chitosan?Gel/CTS?Gel,and RhB-SMIPs-Gel substrate was obtained.Gel substrates with optimal adsorption capacity were obtained by systematically optimizing gelatin mass fraction,chitosan content,solution ratio and powder content.The optimal conditions for the preparation of RhB-SMIPs-Gel are:the mass fraction of gelatin solution is 1%,the addition amount of chitosan is 0.04g/1mL?10%acetic acid?,the ratio of gelatin solution to chitosan is 1?1,the addition amount of RhB-SMIPs powder was 0.05 g/mL?Gel/CTS?.RhB at 0.1 mg/L can be detected in this substrate after the RhB in solution is fully enriched.The base was adsorbed on RhB in the liquid at the same time with Gel/CTS base without RhB-SMIPs powder,and the two bases reached the adsorption equilibrium after 12 h.In anti-interference experiment,the enhancement factor of RhB,Rh6G,sunset yellow,Sudan?and Sudan?were 2.46,0.62,0.22,0.21 and 0.07,respectively.Due to the strong swelling property of this substrate,RhB in beverage,juice and RIO sparkling wine was tested.The results showed that the minimum detection limit of RhB in liquid samples could reach 0.5 mg/L.?3?Study on SMZ-SMIPs-PVA substrate detection in SMZIn this chapter,surface molecularly imprinted polymers?SMZ-SMIPs?with SMZ as template molecules were prepared by SMIP technology.Then,the polymer powder was embedded in the PVA gel.The SMZ-SMIPs-PVA substrate was obtained by optimizing the PVA and gelatin mass fraction,solution ratio and powder addition amount..The optimal conditions for the preparation of SMZ-SMIPs-PVA gel base were as follows:the additive amount of SMZ-SMIPs powder was 0.01 g/mL?PVA?,the proportion of PVA with 6%mass fraction and sodium tetraborate with 4%mass fraction was 5?2.At the excitation wavelength of 285 nm,the SMZ detection limit of the substrate can reach 0.5 mg/L.In the anti-interference experiment,the enhancement factor of SMZ,sulfadimethylpyrimidine,sulfadimidine and sulfadimidine were 2.54,1.20 and 1.20,respectively.Finally,SMZ in river shrimp,crucian carp and yellow croaker was tested.The results showed that the minimum detection limit of SMZ in solid samples could reach 2.5 mg/kg.Due to the high sensitivity of this method,it has shown the advantages of convenience,good selectivity and convenient sample extraction in the actual sample detection,so it is expected to achieve rapid surface detection of pollutants in the environment.