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1 6 3 Vol. 6 No Journal of Food Safety and Quality Mar., 2015 α- 魏小星 1 1,, 胡志雄 2* 1,, 张维农 2*, 齐玉堂 (1., ; 2., ) 1 摘要 : 目的 α-, 方法 α-,,,, α-,, 结果 :, 60, 0.20 mmol, 40 mg, 100 r/min, α-, K d1 =0.995 mmol/l, Q max1 = μmol/g; K d2 =0.458 mmol/l, Q max2 = μmol/g 结论, 200 nm, α- 关键词 : α- ; ; Synthesis of molecularly imprinted microspheres of α-tocopherol and evaluation of their absorption property WEI Xiao-Xing 1, HU Zhi-Xiong 1, 2*, ZHANG Wei-Nong 1, 2*, QI Yu-Tang 1 (1. College of Food Science and Engineering, Wuhan Polytechnic University, Wuhan , China; 2. Hubei Collaborative Innovation Center for Processing of Agricultural Products, Wuhan , China) ABSTRACT: Objective To prepare molecularly imprinted polymer (MIP) microspheres of α-tocopherol by precipitation polymerization and the conditions optimization, moreover, the products absorption property were evaluated. Methods The MIPs of α-tocopherol were synthesized by precipitation polymerization by using methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) and acetonitrile as functional monomer, cross-liker and solution, respectively. The morphology of the MIP microspheres was characterized by scanning electron microscope (SEM) and the corresponding effect factors were optimized. Results The optimal conditions were as follows: acetonitrile as solvent; reaction temperature at 60 ; 0.20 mmol template molecule (α-tocopherol) and 40 mg initiator (azobisisobutyronitrile, AIBN); and stirring speed at 100 r/min. The absorption property and the binding characteristics of the MIPs were evaluated by equilibrium binding experiment and Scatchard analysis. The results showed that two classes of binding sites were produced in the 基金项目 : (Q ) ( ) ( ) Fund: Supported by the Project of Hubei Provincial Department of Education for the Youth (Q ), National Natural Science Foundation of China ( ) and Public Science and Technology Research Projects of State Administration of Grain ( ) * 通讯作者 :,, e_huzhixiong@126.com,, zhangweinong@163.com *Corresponding author: HU Zhi-Xiong, Associate Professor, College of Food Science and Engineering, Wuhan Polytechnic University, No.68, Xuefu Road, Dongxihu District, Wuhan, e_huzhixiong@126.com ZHANG Wei-Nong, Professor, College of Food Science and Engineering, Wuhan Polytechnic University, No.68, Xuefu Road, Dongxihu District, Wuhan, zhangweinong@163.com

2 844 6 polymer matrix, their dissociation constant (K d) and the apparent maximum equilibrium binding capacity (Q max ) were mmol/l, μmol/g for high affinity binding sites and mmol/l, μmol/g for low affinity binding sites. Conclusion Under optimal conditions, the α-tocopherol MIPs showed good morphology of microsphere with particle size around 200 nm and good absorption of α-tocopherol. KEY WORDS: α-tocopherol; molecularly imprinted polymer microspheres; precipitation polymerization 1 引言 (molecular imprinting technique),, ( ) [1-3] (molecularly imprinted polymers, MIPs), [4] [5-8],, MIPs MIPs, MIPs, ; ;,, [9] E, (tocopherol),, 1936,,, [10] α- β- γ- δ- 8, α- (100%)>β- (50%)>γ- (10%)>δ- (1%),,,, [11] [12,13],,, α-, [14], α-,, Puoci [15] MAA EGDMA α-, (solid phase extraction, SPE)- (high performance liquid chromatography, HPLC) α-, α-, α- α-,, α- α-, MAA, EGDMA,, α-, 2 材料与方法 2.1 材料与试剂 α- ( 96%) (MAA)( >99%) (EGDMA)( 98%) (AIBN)( 99%) ; ; ;, 2.2 仪器与设备 DF-1, ; SK3300, ; AR2140, - ; SZ93-1

3 3, : α- 845, ; HH-2, ; S-3000N, ; Thermo-Evolution220, 2.3 实验方法分子印迹聚合物微球的合成 α-, MAA, 1 h,, α- MAA, EGDMA AIBN, 5 min, 10 min N 2,, h,, v( ):v( )=9:1,, 40, α- (MIPs) α- (NIPs) MIPs, 1, 1 : 静态吸附试验 2.0 mmol/l α-, mmol/l 5 ml(v), 20 mg(m),, 12 h, 10 min, 40, 203 nm, (C t ), MIPs α- Q(μmol/g): Q= / =V(C 0 -C t )/m (1) C 0 α- (mmol/l), C t α- (mmol/l), V (L), m MIPs NIPs (g), 3 Table 1 表 1 分子印迹聚合物的合成条件与相应样品标号 The synthesis condition of molecularly imprinted polymers and the corresponding sample label MIPs α- /mmol MAA /mmol EGDMA /mmol AIBN /mmol : /(40 ml) a / /r/min P : P : P : P : P : P : P : P : P : P : P : P : P : P : P : P : P : : a 40 ml;, α- : MAA: EGDMA 1:4:20

4 846 3 食品安全质量检测学报生成的聚合物为单分散微球, 球形较规则, 大小均匀, 结果与讨论 3.1 平均粒径约为 200 nm; 调入少量甲苯后, 聚合物微球沉淀聚合法制备 α-生育酚印迹分子的机制将 α-生育酚分子和 MAA 溶解在弱极性溶剂中, 模板分子 α-生育酚和功能单体 MAA 通过相互作用形成复合物, 加入适量的交联剂 EGDMA 后, 引发剂 (AIBN)使交联剂与模板分子引发聚合, 在 α-生育酚的周围便形成高度交联的刚性聚合物结构, 加入适量洗脱剂将其脱除后, 聚合物中便留下空间结构结合位点与 α-生育酚完全互补的空穴, 最终形成如图 1 所示的 α-生育酚印迹分子聚合物第6卷 α-生育酚分子印迹微球形貌的影响因素粒径变大, 球形不规则且分散性变差当乙腈与甲苯比例小于 4:1 时, 球形逐渐消失而变成无规则形状, 并随着甲苯含量升高趋势越明显这可能是由于乙腈粘度较低, 形成的单分散微球具有较大的流动性, 从而避免了聚集[16] 从以上结果可知, 以纯乙腈溶剂体系进行沉淀聚合可成功合成单分散 MIPs 微球, 且形貌规整, 粒径较小, 比表面积较大, 有利于吸附使用, 故以下实验均以乙腈为溶剂对其他影响因素进行考察反应温度对聚合物形貌的影响一般情况下, 聚合温度越低, 生成的 MIPs 识别性能越好, 但温度过低会无法达到引发剂 AIBN 的热分溶剂对聚合物形貌的影响在合成 α-生育酚分子印迹微球过程中, α-生育酚 MIPs 形貌的影响, 本实验分别在三与功能单体 MAA 是通过较弱的非共价作用形成复合种温度条件下合成相应 MIPs, 其扫描电镜结果如图 3 物的, 极性溶剂会对该作用产生影响, 故选择乙腈甲所示, 从图中可以看出, 随着温度的升高, 聚合物微球苯等弱极性溶剂为宜本实验调节乙腈与甲苯的比例, 的粒径逐渐增大, 这可能是因为温度升高, 溶剂对聚合配制了一系列不同的混合溶剂, 并在该溶剂体系下合物的溶解度变大, 只有当聚合物足够大时, 才能从溶剂成相应聚合物, 以考察溶剂组成对聚合物形貌的影响, 中析出来, 因此聚合物粒径更大综合考虑 MIPs 的形其结果如图 2 所示, 从图中可以看出: 以乙腈为溶剂时, 貌规整性与识别性, 选择在 60 进行聚合较佳 Fig. 1 Fig. 2 解温度, 而不能发生聚合反应为了考察聚合温度对图 1 α-生育酚的结构与分子印迹原理图 The structure of α-tocopherol and schematic diagram of molecular imprinting process 图 2 不同体积比的乙腈甲苯混和溶剂对分子印迹聚合物形貌的影响 (a-1:0, P1; b-16:1, P2; c-8:1, P3; d-4:1, P4; e-2:1, P5; f-1:1, P6; g-1:2, P7; h-0:1, P8) SEM micrographs of MIPs synthesized in the mixture solvent of acetonitrile and toluene at different ratios

第3期 3.2.3 魏小星, 等: α-生育酚分子印迹微球的制备与吸附性能评价引发剂用量对聚合物形貌的影响引发剂是产生自由基聚合反应活性中心的物质, 它不仅影响聚合反应速率, 而且还影响聚合物 847 块状结构从结果比较来看, 引发剂 AIBN 用量以 40 mg 为宜 3.2.4 的相对分子质量偶氮二异丁腈是一种油溶性引发模板用量对聚合物形貌的影响 MIPs 制备过程中, 模板分子浓度越高, 生成的剂, 反应时分解均匀, 只产生一种自由基, 无其他 MIPs 应具有更多的特异性识别位点本实验考察了副作用, 分解速率低, 属于低活性引发剂, 适用于 0.

06 mmol)时, 聚合物中出现极少量粒径聚合物形貌的影响, 所得产物经处理后, 得到扫描差异较大的球形颗粒, 但均匀性很差, 且有部分不规电镜结果如图 4 所示, 从图中可以看出, 引发剂用则块状物, 模板用量大于 0.

30 为缓慢, 聚合不完整所致而当引发剂用量过大(60 mmol 时, 聚合物微球粒径相对较大, 但均匀性较 mg)时, 链引发速率增大, 自由基浓度增大, 聚合 0.20 mmol 时差故聚合过程中模板分子 α-生育酚用过于剧烈, 尚来不及形成球状结构, 而迅速粘结成量以 0.20 mmol 为宜图3 Fig.

5 第3期魏小星, 等: α-生育酚分子印迹微球的制备与吸附性能评价引发剂用量对聚合物形貌的影响引发剂是产生自由基聚合反应活性中心的物质, 它不仅影响聚合反应速率, 而且还影响聚合物 847 块状结构从结果比较来看, 引发剂 AIBN 用量以 40 mg 为宜的相对分子质量偶氮二异丁腈是一种油溶性引发模板用量对聚合物形貌的影响 MIPs 制备过程中, 模板分子浓度越高, 生成的剂, 反应时分解均匀, 只产生一种自由基, 无其他 MIPs 应具有更多的特异性识别位点本实验考察了副作用, 分解速率低, 属于低活性引发剂, 适用于 mmol 四种不同模板用量条件悬浮聚合法和溶液聚合法本实验在合成过程中分下的聚合物形貌, 结果如图 5 所示, 由图可知, 模板别加入 mg AIBN, 以考察引发剂用量对用量很小(0.06 mmol)时, 聚合物中出现极少量粒径聚合物形貌的影响, 所得产物经处理后, 得到扫描差异较大的球形颗粒, 但均匀性很差, 且有部分不规电镜结果如图 4 所示, 从图中可以看出, 引发剂用则块状物, 模板用量大于 0.10 mmol 时球形颗粒较为量太少 (20 mg)时, 聚合物颗粒较小, 球形尚未完完整, 分散性较好, 但微球粒径及均匀性有所差异, 全形成, 且粘结现象较严重, 这可能是由于反应较用量为 0.20 mmol 时聚合物均匀性更好, 用量为 0.30 为缓慢, 聚合不完整所致而当引发剂用量过大(60 mmol 时, 聚合物微球粒径相对较大, 但均匀性较 mg)时, 链引发速率增大, 自由基浓度增大, 聚合 0.20 mmol 时差故聚合过程中模板分子 α-生育酚用过于剧烈, 尚来不及形成球状结构, 而迅速粘结成量以 0.20 mmol 为宜图3 Fig.3 反应温度对分子印迹聚合物形貌的影响 (a-60, P1; b-70, P9; c-80, P10) SEM micrographs of MIPs synthesized under different polymerization temperatures 图4 Fig.4 引发剂用量对分子印迹聚合物形貌的影响 (a-20 mg, P11; b-40 mg, P1; c-60 mg, P12) SEM micrographs of MIPs synthesized under different initiator concentrations 图 5 模板用量对分子印迹聚合物形貌的影响 (a-0.06 mmol, P13; b-0.10 mmol, P14; c-0.20 mmol, P1; d-0.3 mmol, P15) Fig.5 SEM micrographs of MIPs synthesized under different template concentrations

848 6 Fig. 6 6 (a-0 r/min, P 16 ; b-50 r/min, P 17 ; c-100 r/min, P 1 ) SEM micrographs of MIPs synthesized under different rotational speeds 3.2.

6 848 6 Fig. 6 6 (a-0 r/min, P 16 ; b-50 r/min, P 17 ; c-100 r/min, P 1 ) SEM micrographs of MIPs synthesized under different rotational speeds 转速大小对聚合物形貌的影响 MIPs,,, r/min, 6,,,, MIPs 230 nm, r/min MIPs 200 nm,,,, [17] ;,,,, 100 r/min 3.3 α- 生育酚分子印迹微球的吸附性能评价 mmol/l α-, 203 nm,, : Y=(35.023±1.400) * X+ (0.158±0.055) (n=6; r 2 =0.997), α- Scatchard 吸附等温线 α-, 2.3.2, Q, MIPs NIPs, 7,, 0.2~2 mmol/l, MIPs α-, NIPs, MIPs,, α- MIPs Scatchard 分析 Scatchard, Q/C=(Q max -Q)/K d (2), C α- (mmol/l), Q max (μmol/g), K d (mmol/l) Fig. 7 7 MIPs NIPs The absorption capacity of MIPs and NIPs to α-tocopherol 8 Q/C Q Scatchard, Q/C Q, MIPs α-,,,, MIPs α-, Q/C t = Q Q/C t = Q, K d =0.995 mmol/l, Q max = μmol/g; K d =0.458 mmol/l, Q max = μmol/g,, α-,,

7 3, : α- 849 [J]. J Chromatog A, 2014, 1364(17): [6] Tiwari MP, Vitae A, Prasad A, et al. Molecularly imprinted polymer based enantioselective sensing devices: A review [J]. Anal Chim Acta, 2015, 853(1): [7] Huang CY, O'Hare D, Chao IJ, et al. Integrated potentiostat for electrochemical sensing of urinary 3-hydroxyanthranilic acid with molecularly imprinted poly(ethylene-co-vinyl alcohol) [J]. Bionsens Bioelectron, 2015, 67(15): [8] Kong Y, Shan XL, Ma JF, et al. A novel voltammetric sensor for ascorbic acid based on molecularly imprinted poly(o-phenylenediamine-co-o-aminophenol) [J]. Anal Chim Acta, 2014, 809(27): Fig. 8 8 MIPs Scatchard Scatchard plot to estimate the adsorption properties of MIPs [9]. [D]. :, Cheng FQ. Preparation and properties of chenodeoxycholic acid 4 结论 α-,, α-, :, 60, 0.20 mmol, 40 mg, 100 r/min, α- K d1 =0.995 mmol/l, Q max1 = μmol/g; K d2 =0.458 mmol/l, Q max2 = μmol/g 参考文献 [1] Lei J, He X, Tan T. Molecular imprinting and its applications [J]. Mod Chem Ind, 2001, 21(4): [2] Ekberg B, Mosbach K. Molecular imprinting: A technique for producing specific separation materials [J]. Trend Biotechnol, 1989, 7(4): [3] Asanuma H, Hishiya T, Komiyama M. Tailor-made receptors by molecular imprinting [J]. Adv Mater, 2000, 12(14): [4] Xu ZX, Gao HJ, Zhang LM, et al. The Biomimetic Immunoassay Based on Molecularly Imprinted Polymer: A Comprehensive Review of Recent Progress and Future Prospects [J]. J Food Sci, 2011, 76(2): R69 R75. [5] Szumski M, Grzywiński D, Prus W, et al. Monolithic molecularly imprinted polymeric capillary columns for isolation of aflatoxins molecularly imprinted polymer microspheres [D]. Xian: Shanxi Normal University, [10],,,. E [J]., 2011, 38(220): Li L, Xue B, Gao L, et al. The natural vitamin E and its preparation process [J]. Guandong Chem Ind, 2011, 38(220): [11] Panfil IG, Fratianni A, Irano M. Normal phase high-performance liquid chromatography method for the determination of tocopherols and tocotrienols in cereals [J]. Anal Chem, 2003, 51: [12] Muller DP, Lloyd JK, Wolff OH. The role of vitamin E in the treatment of the neurological features of abetalipoproteinaemia and other disorders of fat absorption [J]. Inherit Metab, 1985, 8(1): [13] Chow CK. Biological function and metabolic fate of vitamin E revisited [J]. Biomed Sci, 2004, 11: [14],. α- [J]., 2011, 2: Zhang XF, Wang T. Regulation of α-tocopherol and its derivatives on animal growth and development [J]. China Feed, 2011, 2: [15] Puoci F, Cirillo G, Curcio M. Molecularly imprinted solid phase extraction for the selective HPLC determination of α-tocopherol in bay leaves [J]. Anal Chim Acta, 2007, 593:

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com 胡志雄, 副教授, 主要研究方向为粮食油脂与植物蛋白工程 E-mail: e_huzhixiong@126.com [J]., 2005, 12(1): 36 38.

8 850 6 [16],,,. 4- 作者简介 [J]., 2001, 22(3): Guo HS, Jia YM, Cao XF, et al. Characterization and synthesis of microspherical 4-aminopyridine molecular template polymer [J]. Chem J Chin Univ, 2001, 22(3): [17],,,. 魏小星, 硕士研究生, 主要研究方向为油脂质量与安全控制 @163.com 胡志雄, 副教授, 主要研究方向为粮食油脂与植物蛋白工程 e_huzhixiong@126.com [J]., 2005, 12(1): Li FH, Fan Y, Wang FJ, et al. The effects of stirring condition on particle size [J]. Chem Product Technol, 2005, 12(1): ( 责任编辑 : 白洪健 ) 张维农, 教授, 主要研究方向为油料资源综合开发 zhangweinong@163.com

材料导报研究篇年月下第卷第期种球的制备单步溶胀法制备分子印迹聚合物微球洗脱处理种子溶胀聚合机理种球用量的影响

材料导报研究篇年月下第卷第期种球的制备单步溶胀法制备分子印迹聚合物微球洗脱处理种子溶胀聚合机理种球用量的影响水相中组氨酸单分散分子印迹聚合物微球的合成表征及其识别性能研究李思平等李思平徐伟箭较佳工艺条件下在水性体系中选用无皂乳液聚合法制得的单分散微米级聚苯乙烯微球为种球分别以组氨酸甲基丙烯酸或丙烯酸胺乙二醇二甲基丙烯酸酯为模板分子功能单体和交联剂合成了组氨酸分子印迹聚合物微球研究了形貌粒径及其分布以及模板分子与功能单体之间的相互作用分别以激光粒度分析仪紫外分光光度法和红外光谱表征功能单体与交联剂之间的共聚情况