Research On The Synthesis, Characterization And Application Of Amino Acid Surface Molecularly Imprinting Polymer

In this paper, the research progress and development trend in:technology of separation and enrichment of amino acids in tobacco and tobacco smoke, preparation of surface molecularly imprinted polymer, molecularly imprinted polymer-solid phase extraction, dummy template surface molecularly imprinted polymer were reviewed. Study on the direct preparation of alanine molecularly imprinted polymer on surface of silica microspheres was explored and its separation and enrichment performance towards alanine was discussed. Dummy molecularly imprinted polymers of amino acids on the surface of silica microspheres was synthesized as the new packing of the solid phase extraction, and applied to the determination of amino acids in tobacco and tobacco smoke samples. A new method of molecularly imprinted solid phase extraction-high performance liquid chromatography (HPLC) was established to determine the content of amino acids in samples.Vinyl-functionalized silica microspheres were directly synthesized via a one-step method. Fourier infrared spectrum, scanning electron microscopy, transmission electron microscopy had been used to characterize the properties such as physical morphology of the result silica microspheres. It turned out to show that the silica microspheres could provide as an ideal carrier in the preparation of molecularly imprinted polymer, for its good homogeneity and single dispersion.Alanine molecularly imprinted polymer (SMIPs) was prepared on the surface of the silica microspheres, and characterized by Fourier infrared spectrum, scanning electron microscopy, transmission electron microscopy. The performance of enrichment and separation of alanine and repeat utilization were evaluated. Studies had shown that the SMIPs had good adsorption capability to alanine, with an equilibrium adsorption of 831μmol g-1 and a short period to achieve dynamic balance (49.37% of equilibrium adsorption could be finished within 30 minutes). SMIPs showed good specificity, affinity and regeneration performance of alanine.The analogue of amino acids, theanine (The) as the dummy template, theanine molecularly imprinted polymer (DMIPs) was synthesized successfully on the surface of silica microspheres. The result materials were characterized by scanning electron microscope, transmission electron microscopy and infrared spectrum. The adsorption capacity of DMIPs was also tested, and results showed thatDMIPs owned a high adsorption capacity towards amino acids (1444.3 mg g’1), and the adsorption equilibrium could be reached in 25 min. Meanwhile, the material displayed high selectivity and special affinity to amino acids. The material laid a foundation for establishing a method to determine and analyze amino acids in samples.Apply the DMIPs to solid phase extraction (SPE) as new packing materials to concentrate and separate trace amino acids in real samples. Conjunction with high performance liquid chromatography (HPLC), DMIPs-SPE-HPLC was established as a new method to determine the content of amino acids in real samples. Studies showed that DMIPs-SPE enrichment ratio of amino acids could be as high as 200. In conditions with coexisting of amino acids of different concentrations, DMIPs-SPE still showed the selective extraction effect and reusable performance of amino acids. When applying to the determination of amino acids in tobacco and tobacco smoke samples, the established DMIPs-SPE-HPLC method owned a linear range of 10-1000 ng mL-1 with a correlation coefficient almost 0.999, and the range of detection limit of amino acids was 0.094-0.374 ng mL-1. The recovery rate of spiked water samples was between 79 and 104%.