溴氰菊酯农药残留检测的分子印迹预聚体系筛选及吸附性能
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摘要
为快速筛选及确定合适的预聚体系,以高效制备对茶叶等食品中残留的溴氰菊酯具有特异识别能力的分子印迹聚合物,以溴氰菊酯为模板,采用Materials Studio软件和紫外光谱对预聚体系中功能单体和溶剂进行种类筛选及配比确定,辅助溴氰菊酯分子印迹聚合物的合成设计。对模板与不同功能单体预聚体系的结合能计算和光谱分析结果均表明溴氰菊酯与丙烯酰胺能形成更为稳定的复合物,且以乙腈为溶剂更有利于溴氰菊酯分子印迹聚合物的制备。差示紫外光谱计算进一步得出当溴氰菊酯与丙烯酰胺的化学配位比n=4时,可在乙腈溶液中形成稳定的预聚体系,其结合常数为6.614×10~5。基于上述结果,采用沉淀聚合法正交优化制备溴氰菊酯分子印迹聚合物,扫描电镜和静态平衡吸附试验结果表明所制备聚合物具有良好的多孔结构和特异吸附性,印迹因子为2.269,对3种结构类似物的分离因子均大于3.2。研究结果表明分子模拟和光谱分析方法对分子印迹预聚体系筛选和聚合物合成设计具有重要的指导意义。
To efficiently prepare decamethrin molecular(DM) imprinted polymers, the molecular dynamics simulation and ultraviolet spectrum were involved to study the preassembled system of DM and functional monomers in this paper. The binding energy(?E) between DM and three different functional monomers(acrylic acid, AA; acrylamide, AM; methacrylic acid, MAA) in different solvents(n-hexane, chloroform, acetone and acetonitrile) were calculated by molecular dynamics simulation. Results showed that the AM monomer and acetonitrile solvent had the highest stabilization energy for the pre-polymerization adducts. Additionally, the polymer obtained from the molar ratio of DM to AM at 1:4 to 1:6 may be more stable. Ultraviolet spectrum analysis results showed that there was strong interaction between DM and AM, the red shift degree of ultraviolet spectrum maximum absorption peak followed the order: AM > AA = MAA, and then indicated that AM was most suitable monomers for DM molecular imprinted polymers, which was consistent with the predictions based on the computer simulation. Differential ultraviolet spectrum showed that when acetonitrile used as solvent, one DM molecule could be combined with AA monomer in the ratio of 1:3 or AM monomer in the ratio of 1:4. However, it was difficult for DM to form stable complex with MAA because the fitting correlation coefficient of the equation was less than 0.86. Best performance was observed when chemical coordination ratio(n) between DM and AM was equal to 4, at this time, the fitting correlation coefficient of the equation was 0.997 3, and the binding constant K was 6.614×10~5. Based on the above computer simulation and ultraviolet spectrum analysis results, the molecularly imprinted polymers of DM were synthesized by the precipitation polymerization method with the AM as the functional monomer, and its synthetic formula was optimized through orthogonal experiment design. Then, the optimum imprinting conditions were established: 1 mmol DM as the template molecule, 4 mmol AM as the functional monomers, 40 mL acetonitrile as the solvent, 20 mmol ethylene dimethacrylate(EGDMA) as the cross-linker. Using these conditions, the DM molecular imprinted polymers had bigger saturated adsorption capacity of 68.61 mg/g than other conditions. The prepared molecular imprinted polymers were characterized by scanning electron microscopy(SEM), brunauer-emmett-teller(BET) and Fourier transform infrared spectroscopy(FTIR). SEM demonstrates that the DM molecular imprinted polymers formed staggered porous structure. The data of BET revealed that the DM molecular imprinted polymers had smaller pore size(15.83 nm) than non-imprinted polymers(18.84 nm), but with a larger specific surface area(95.58 m~2/g) and pore volume(0.578 5 cm3/g). The FTIR results confirmed the successful preparation of the DM molecular imprinted polymers. And then the adsorption selectivity of prepared polymers on deltamethrin and its analogues cypermethrin, lambda-cyhalothrin and bifenthrin were studied. The experimental results showed that the static equilibrium adsorption capacity and static distribution coefficient of DM was much higher than that of other analogues. Its imprinting factor(IF) was 2.269, and the corresponding separation factor α was more than 3.2, which has exhibited obvious specific identification. All above results showed that computer simulation and ultraviolet spectrum analysis could help to design the better performance molecular imprinted polymers.
To efficiently prepare decamethrin molecular(DM) imprinted polymers, the molecular dynamics simulation and ultraviolet spectrum were involved to study the preassembled system of DM and functional monomers in this paper. The binding energy(?E) between DM and three different functional monomers(acrylic acid, AA; acrylamide, AM; methacrylic acid, MAA) in different solvents(n-hexane, chloroform, acetone and acetonitrile) were calculated by molecular dynamics simulation. Results showed that the AM monomer and acetonitrile solvent had the highest stabilization energy for the pre-polymerization adducts. Additionally, the polymer obtained from the molar ratio of DM to AM at 1:4 to 1:6 may be more stable. Ultraviolet spectrum analysis results showed that there was strong interaction between DM and AM, the red shift degree of ultraviolet spectrum maximum absorption peak followed the order: AM > AA = MAA, and then indicated that AM was most suitable monomers for DM molecular imprinted polymers, which was consistent with the predictions based on the computer simulation. Differential ultraviolet spectrum showed that when acetonitrile used as solvent, one DM molecule could be combined with AA monomer in the ratio of 1:3 or AM monomer in the ratio of 1:4. However, it was difficult for DM to form stable complex with MAA because the fitting correlation coefficient of the equation was less than 0.86. Best performance was observed when chemical coordination ratio(n) between DM and AM was equal to 4, at this time, the fitting correlation coefficient of the equation was 0.997 3, and the binding constant K was 6.614×10~5. Based on the above computer simulation and ultraviolet spectrum analysis results, the molecularly imprinted polymers of DM were synthesized by the precipitation polymerization method with the AM as the functional monomer, and its synthetic formula was optimized through orthogonal experiment design. Then, the optimum imprinting conditions were established: 1 mmol DM as the template molecule, 4 mmol AM as the functional monomers, 40 mL acetonitrile as the solvent, 20 mmol ethylene dimethacrylate(EGDMA) as the cross-linker. Using these conditions, the DM molecular imprinted polymers had bigger saturated adsorption capacity of 68.61 mg/g than other conditions. The prepared molecular imprinted polymers were characterized by scanning electron microscopy(SEM), brunauer-emmett-teller(BET) and Fourier transform infrared spectroscopy(FTIR). SEM demonstrates that the DM molecular imprinted polymers formed staggered porous structure. The data of BET revealed that the DM molecular imprinted polymers had smaller pore size(15.83 nm) than non-imprinted polymers(18.84 nm), but with a larger specific surface area(95.58 m~2/g) and pore volume(0.578 5 cm3/g). The FTIR results confirmed the successful preparation of the DM molecular imprinted polymers. And then the adsorption selectivity of prepared polymers on deltamethrin and its analogues cypermethrin, lambda-cyhalothrin and bifenthrin were studied. The experimental results showed that the static equilibrium adsorption capacity and static distribution coefficient of DM was much higher than that of other analogues. Its imprinting factor(IF) was 2.269, and the corresponding separation factor α was more than 3.2, which has exhibited obvious specific identification. All above results showed that computer simulation and ultraviolet spectrum analysis could help to design the better performance molecular imprinted polymers.
引文
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[7]Mariusz M,Teobald K,Piotr P W,et al.Computational modeling of molecularly imprinted polymers as a green approach to the development of novel analytical sorbents[J].Trends in Analytical Chemistry,2018,98:64-78.
[8]Han Yi,Gu Lili,Zhang Mengxiao,et al.Computer-aided design of molecularly imprinted polymers for recognition of atrazine[J].Computational and Theoretical Chemistry,2017,1121:29-34.
[9]黄雨杰,朱秋劲,赵晓联.紫外光谱与密度泛函理论在亚精胺分子印迹预组装体系中的研究[J].北京化工大学学报:自然科学版,2014(4):48-54.Huang Yujie,Zhu Qiujin,Zhao Xiaolian.Ultraviolet spectroscopy and density functional theory study of spermidine molecularly imprinted pre-assembly systems[J].Journal of Beijing University of Chemical Technology:Natural Science,2014(4):48-54.(in Chinese with English abstract)
[10]尹小英,衷友泉,江一帆,等.分子印迹聚合反应中功能单体与模板分子间作用力的光谱分析[J].光谱学与光谱分析,2010(8):2211-2214.Yin Xiaoying,Zhong Youquan,Jiang Yifan,et al.The spectroscopy analysis of intermolecular interaction between the template molecule and functional monomer before polymerization[J].Spectroscopy and Spectral Analysis,2010(8):2211-2214.(in Chinese with English abstract)
[11]朱晓兰.久效磷分子印迹聚合物的研究与应用[D].合肥:中国科学技术大学,2006.Zhu Xiaolan.Monocrotophos-specific Molecular Imprinted Polymers and its Applications for Analysis of Organophosphorus Pesticides[D].Hefei:University of Science&Technology of China,2006.(in Chinese with English abstract)
[12]Farrington K,Magner E,Regan F.Predicting the performance of molecularly imprinted polymers:Selective extraction of caffeine by molecularly imprinted solid phase extraction[J].Analytica Chimica Acta,2006,566(1):60-68.
[13]Yang Wenming,Liu Lukuan,Zhou Zhiping,et al.Rational preparation of dibenzothiophene-imprinted polymers by surface imprinting technique combined with atom transfer radical polymerization[J].Applied Surface Science,2013,282:809-819.
[14]Chen Lingxin,Wang Xiaoyan,Lu Wenhui,et al.Molecular imprinting:Perspectives and applications[J].Chemical Society Reviews,2016,45(8):2137-2211.
[15]Martins N,Carreiro E P,Locati A,et al.Design and development of molecularly imprinted polymers for the selective extraction of deltamethrin in olive oil:An integrated computational-assisted approach[J].Journal of Chromatography A,2015,1409:1-10.
[16]郭逸蓉.计算机辅助设计拟除虫菊酯类农药分子印迹聚合物研制[D].杭州:浙江大学,2010.Guo Yirong.Computer-assisted Design for the Preparation of Molecularly Imprinted Polymers for Pyrethroid Pesticides[D].Hangzhou:Zhejiang University,2010.(in Chinese with English abstract)
[17]戴芳芳.溴氰菊酯电化学快速检测及分子印迹预组装体系研究[D].重庆:西南大学,2016.Dai Fangfang.Research on Deltamethri`s Rapid Detection by Electrochemical Merhod and Molecular Imprinting Preassembly System[D].Chongqing:Southwest University,2016.(in Chinese with English abstract)
[18]Bakas I,Oujji N B,Moczko E,et al.Computational and experimental investigation of molecular imprinted polymers for selective extraction of dimethoate and its metabolite omethoate from olive oil[J].Journal of Choromatography A,2013,1274(1):13-18.
[19]朱淮武.有机分子结构波谱解析[M].北京:化学工业出版社,2005.
[20]高文惠,高林,刘博,等.制备戊唑醇分子印迹聚合物前功能单体的选择[J].中国食品学报,2015,15(6):173-177.Gao Wenhui,Gao Lin,Liu Bo,et al.Selection of functional monomer before the preparation of tebuconazole molecularly imprinted polymer[J].Journal of Chinese Institute of Food Science and Technology,2015,15(6):173-177.(in Chinese with English abstract)
[21]张孝刚,朱秋劲,胡萍.三聚氰胺分子印迹预组装体系紫外光谱研究[J].食品科学,2011,32(21):128-132.Zhang Xiaogang,Zhu Qiujin,Hu Ping.Ultraviolet spectroscopy investigation into molecular imprinting pre-assembly system[J].Food Science,2011,32(21):128-132.(in Chinese with English abstract)
[22]Cormack P A G,Elorza A Z.Molecularly imprinted polymers:Synthesis and characterisation[J].Journal of Chromatography B Analytical Technologies in the Biomedical and Life Sciences,2004,804(1):173-182.
[23]张连科,刘心宇,王维大,等.油料作物秸秆生物炭对水体中铅离子的吸附特性与机制[J].农业工程学报,2018,34(7):218-226.Zhang Lianke,Liu Xinyu,Wang Weida,et al.Characteristics and mechanism of lead adsorption from aqueous solutions by oil crops straw-derived biochar[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2018,34(7):218-226.(in Chinese with English abstract)
[24]Chrzanowska A M,Poliwoda A,Wieczorek P P.Characterization of particle morphology of biochanin A molecularly imprinted polymers and their properties as a potential sorbent for solid-phase extraction[J].Materials Science and Engineering:C,2015,49:793-798.
[25]Wang Hongwu,Liu Yanqing,Yao Su,et al.Selective recognization of dicyandiamide in bovine milk by mesoporous silica SBA-15 supported dicyandiamide imprinted polymer based on surface molecularly imprinting technique[J].Food Chemistry,2018,240:1262-1267.
[26]庞思思.沉淀制备双酚Aπ-π堆积自组装印迹聚合物及其特异性识别机理研究[J].高分子学报,2014(1):49-55.Pang Sisi.Synthesis of bisphenol-A stacking self-assembly imprinted polymer by precipitation polymerization and study on specificity recognition mechanism[J].Acta Polymerica Sinica,2014(1):49-55.(in Chinese with English abstract)
[27]佘永新,王淼,史晓梅,等.类特异性分子印迹聚合物微球的识别机理及其光谱学研究[J].光谱学与光谱分析,2010,30(11):3052-3055.She Yongxin,Wang Miao,Shi Xiaomei,et al.Spectroscopy study of binding mechanisms and molecular recognition of class-specific molecularly imprinted polymer beads[J].Spectroscopy and Spectral Analysis,2010,30(11):3052-3055.(in Chinese with English abstract)
[2]Liu Pengyan,Liu Yujie,Liu Qingxue,et al.Photodegradation mechanism of deltamethrin and fenvalerate[J].Journal of Environmental Sciences,2010,22(7):1123-1128.
[3]Rehman H,Ali M,Atif F,et al.The modulatory effect of deltamethrin on antioxidants in mice[J].Clinica Chimica Acta,2006,369(3):61-65.
[4]赵风年.基于磁性纳米分子印迹技术的三唑类农药多残留检测方法研究[D].北京:中国农业科学院,2017.Zhao Fengnian.Study on the Multi-residues Detection of Triazole Pesticides Based on Magnetic Nano Molecularly Imprinted Technology[D].Beijing:Chinese Academy of Agricultural Sciences Dissertation,2017.(in Chinese with English abstract)
[5]Ge Shengguang,Lu Juanjuan,Ge Lei,et al.Development of a novel deltamethrin sensor based on molecularly imprinted silica nanospheres embedded CdTe quantum dots[J].Spectrochimica Acta Part A:Molecular and Biomolecular Spectroscopy,2011,79(5):1704-1709.
[6]Shi Xizhi,Liu Jinghua,Sun Aili,et al.Group-selective enrichment and determination of pyrethroid insecticides in aquaculture seawater via molecularly imprinted solid phase extraction coupled with gas chromatography-electron capture detection[J].Journal Chromatogr A,2012,1227:60-66.
[7]Mariusz M,Teobald K,Piotr P W,et al.Computational modeling of molecularly imprinted polymers as a green approach to the development of novel analytical sorbents[J].Trends in Analytical Chemistry,2018,98:64-78.
[8]Han Yi,Gu Lili,Zhang Mengxiao,et al.Computer-aided design of molecularly imprinted polymers for recognition of atrazine[J].Computational and Theoretical Chemistry,2017,1121:29-34.
[9]黄雨杰,朱秋劲,赵晓联.紫外光谱与密度泛函理论在亚精胺分子印迹预组装体系中的研究[J].北京化工大学学报:自然科学版,2014(4):48-54.Huang Yujie,Zhu Qiujin,Zhao Xiaolian.Ultraviolet spectroscopy and density functional theory study of spermidine molecularly imprinted pre-assembly systems[J].Journal of Beijing University of Chemical Technology:Natural Science,2014(4):48-54.(in Chinese with English abstract)
[10]尹小英,衷友泉,江一帆,等.分子印迹聚合反应中功能单体与模板分子间作用力的光谱分析[J].光谱学与光谱分析,2010(8):2211-2214.Yin Xiaoying,Zhong Youquan,Jiang Yifan,et al.The spectroscopy analysis of intermolecular interaction between the template molecule and functional monomer before polymerization[J].Spectroscopy and Spectral Analysis,2010(8):2211-2214.(in Chinese with English abstract)
[11]朱晓兰.久效磷分子印迹聚合物的研究与应用[D].合肥:中国科学技术大学,2006.Zhu Xiaolan.Monocrotophos-specific Molecular Imprinted Polymers and its Applications for Analysis of Organophosphorus Pesticides[D].Hefei:University of Science&Technology of China,2006.(in Chinese with English abstract)
[12]Farrington K,Magner E,Regan F.Predicting the performance of molecularly imprinted polymers:Selective extraction of caffeine by molecularly imprinted solid phase extraction[J].Analytica Chimica Acta,2006,566(1):60-68.
[13]Yang Wenming,Liu Lukuan,Zhou Zhiping,et al.Rational preparation of dibenzothiophene-imprinted polymers by surface imprinting technique combined with atom transfer radical polymerization[J].Applied Surface Science,2013,282:809-819.
[14]Chen Lingxin,Wang Xiaoyan,Lu Wenhui,et al.Molecular imprinting:Perspectives and applications[J].Chemical Society Reviews,2016,45(8):2137-2211.
[15]Martins N,Carreiro E P,Locati A,et al.Design and development of molecularly imprinted polymers for the selective extraction of deltamethrin in olive oil:An integrated computational-assisted approach[J].Journal of Chromatography A,2015,1409:1-10.
[16]郭逸蓉.计算机辅助设计拟除虫菊酯类农药分子印迹聚合物研制[D].杭州:浙江大学,2010.Guo Yirong.Computer-assisted Design for the Preparation of Molecularly Imprinted Polymers for Pyrethroid Pesticides[D].Hangzhou:Zhejiang University,2010.(in Chinese with English abstract)
[17]戴芳芳.溴氰菊酯电化学快速检测及分子印迹预组装体系研究[D].重庆:西南大学,2016.Dai Fangfang.Research on Deltamethri`s Rapid Detection by Electrochemical Merhod and Molecular Imprinting Preassembly System[D].Chongqing:Southwest University,2016.(in Chinese with English abstract)
[18]Bakas I,Oujji N B,Moczko E,et al.Computational and experimental investigation of molecular imprinted polymers for selective extraction of dimethoate and its metabolite omethoate from olive oil[J].Journal of Choromatography A,2013,1274(1):13-18.
[19]朱淮武.有机分子结构波谱解析[M].北京:化学工业出版社,2005.
[20]高文惠,高林,刘博,等.制备戊唑醇分子印迹聚合物前功能单体的选择[J].中国食品学报,2015,15(6):173-177.Gao Wenhui,Gao Lin,Liu Bo,et al.Selection of functional monomer before the preparation of tebuconazole molecularly imprinted polymer[J].Journal of Chinese Institute of Food Science and Technology,2015,15(6):173-177.(in Chinese with English abstract)
[21]张孝刚,朱秋劲,胡萍.三聚氰胺分子印迹预组装体系紫外光谱研究[J].食品科学,2011,32(21):128-132.Zhang Xiaogang,Zhu Qiujin,Hu Ping.Ultraviolet spectroscopy investigation into molecular imprinting pre-assembly system[J].Food Science,2011,32(21):128-132.(in Chinese with English abstract)
[22]Cormack P A G,Elorza A Z.Molecularly imprinted polymers:Synthesis and characterisation[J].Journal of Chromatography B Analytical Technologies in the Biomedical and Life Sciences,2004,804(1):173-182.
[23]张连科,刘心宇,王维大,等.油料作物秸秆生物炭对水体中铅离子的吸附特性与机制[J].农业工程学报,2018,34(7):218-226.Zhang Lianke,Liu Xinyu,Wang Weida,et al.Characteristics and mechanism of lead adsorption from aqueous solutions by oil crops straw-derived biochar[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2018,34(7):218-226.(in Chinese with English abstract)
[24]Chrzanowska A M,Poliwoda A,Wieczorek P P.Characterization of particle morphology of biochanin A molecularly imprinted polymers and their properties as a potential sorbent for solid-phase extraction[J].Materials Science and Engineering:C,2015,49:793-798.
[25]Wang Hongwu,Liu Yanqing,Yao Su,et al.Selective recognization of dicyandiamide in bovine milk by mesoporous silica SBA-15 supported dicyandiamide imprinted polymer based on surface molecularly imprinting technique[J].Food Chemistry,2018,240:1262-1267.
[26]庞思思.沉淀制备双酚Aπ-π堆积自组装印迹聚合物及其特异性识别机理研究[J].高分子学报,2014(1):49-55.Pang Sisi.Synthesis of bisphenol-A stacking self-assembly imprinted polymer by precipitation polymerization and study on specificity recognition mechanism[J].Acta Polymerica Sinica,2014(1):49-55.(in Chinese with English abstract)
[27]佘永新,王淼,史晓梅,等.类特异性分子印迹聚合物微球的识别机理及其光谱学研究[J].光谱学与光谱分析,2010,30(11):3052-3055.She Yongxin,Wang Miao,Shi Xiaomei,et al.Spectroscopy study of binding mechanisms and molecular recognition of class-specific molecularly imprinted polymer beads[J].Spectroscopy and Spectral Analysis,2010,30(11):3052-3055.(in Chinese with English abstract)