The Preparation Method Of Sudan Ⅰ Molecular Imprinting Polymers With Performance Characterization

Sudan Red is a kind of synthetic azo dye used widely. Due to its potential carcinogenicity, Sudan Red is forbidden to use in food and limited in environment. Molecular imprinted polymers (MIPs) have been verified to be much specific and affinity toward the target species, and thus developing a facile and rapid analytical method to effectively detect Sudan Red is significant and necessary. In this work, different molecular imprinted polymers for Sudan I have been fabricated by bulk polymerization and surface molecular imprinted polymerization. And the properties and absorption performance of the obtained polymers was studied in detail, which is in favor of providing potential means for separation and purification of Sudan I in complex samples.In the thesis, three parts are involved and listed as follows.In chapter 1, review. The developments of analytic methods and pretreatment technologies for Sudan Red dye have been introduced. The prime principle, characteristics, evaluation indexs, and the preparation methods of MIPs are also presented. The progress and current of the research on MIPs for Sudan Red are stated, and then the aim and experimental scheme of this thesis are put forward briefly.In charpter 2, the MIPs for Sudan I has been prepared in chloroform by bulk polymerization method. The characteristics and absorption performance of the MIPs have been also investigated. The adsorption kinetic curve could reach the equilibrium in 12 hours when the concentration of Sudan I is of 20 μg/mL-1 With the augment of Sudan I in the range from 0.5 to 20.0 μg·mL-1, the absorption capacity of MIPs increases continuously and gains the maximum value of 480 μg·g-1, which is 4.8 times more than that of non-MIPs. Two different affinity data toward Sudan I in the adsorption process were observed with Scatchard analysis, and the maximum apparent absorption value could be obtained at 312 μg·g-1 and 1199 μg·g-1 respectively. The selectivity of Sudan I is acceptable and the selectivity factor for Sudan II-IV are 3.40、2.21 and 6.82, respectively.In chapter 3, a new MIPs for Sudan I has been fabricated by using surface polymerization with a sol-gel method, which might overcome the shortcoming oftenly exists in bulk polymerization such as long time-consuming process, slow mass transfer and deep embedding. Effects of polymerization temperature and mixed solution on the selectivity of MIPs for Sudan I are investigated, and the combining ability and selectivity factor are also evaluated. When the concentration is at 10.0 μg.mL-1, the absorption capacity gains the value of 103 μg.g-1, which is 2.1 times as much as that of NIPs. Besides, the influence of the elution solution on the mass transfer of MIPs is also discussed. The results indicated that the MIPs showed specific affinity and faster mass transfer in the centain solution with CH3OH/H2O (1:9, v/v). A rapid process to reach the adsorption-desorbtion equilibrum could be gain in 10 minutes when the concentration of Sudan I is of 5.0 μg·mL-1,which is better than that of bulk polymerization. It might be a potential molecularly imprinted polymer for the rapid selective pretrement of Sudan I when some modification has been done in future.