Analyzation Of Special Organics In Environment By Molecularly Imprinted Sold-phase Extraction

Molecular Imprinting technique(MIT) is a kind of emerging technology for manufacturing polymers with specific selectivity to the target molecule. MIT is a cross-technology of muti-subject. And it’s often described as a way of making a molecular lock to match a molecular key. Molecularly imprinted polymers (MIP) are synthetic materials with artificially generated recognition sites able to specifically rebind a target molecule. Molecularly imprinted polymers have been applied in solid phase extraction, catalyzed synthesis,thesevparation, membrane separation, and biomimetic sensors for its good performance.However, nowadays the use of MIP in solid-phase extraction, so-called molecularly imprinted solid-phase extraction (MISPE), is an investigative hot spots in recent years. Suspension polymerization is a well-developed method in synthesis of molecularly imprinted polymers, which is an effective method for synthesis of molecularly imprinted polymer microspheres. This dissertation takes sulfadiazine and PSP toxins as the research objects. MIP were prepared by precipitation polymerization, used as solid-phase extraction sorbents, and then combined to HPLC for detection of sulfadiazine in eggs and PSP toxins in sea water. It provides a reference way for the analysis of corresponding matter.The primary research in the dissertation was as follows:1) Sulfadiazine a kind of broad spectrum antibiotics is widely used in poultry breeding and can remain in vivo. Therefore, to take effective measures to monitor content of sulfadiazine has very important significance. In this chapter, a highly selective sample beneficiation procedure combined with MISPE was developed for sulfadiazine in egg samples. The MIP was prepared through suspension polymerization method using sulfadiazine as the template molecule, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking monomer. Systematic investigations of synthetic conditions were conducted and equilibrium binding experiments were performed. Then the obtained MIP was used as selective sorbent for the solid-phase extraction. An MISPE method followed by HPLC detection for the analysis of sulfadiazine was established. The recoveries for sulfadiazine standard solution were in the range of 78.2%-86.1%. Finally, the sulfadiazine in eggs was determined using this method. It was demonstrated that the proposed MISPE-HPLC method could be applied to direct determination of SDZ in eggs which omitted the procedure of nitrogen blowing and removing the fat.2) With the development of studies on PSP toxins and the demand for standard toxin, the separation and purification for toxins have attracted broad attention. Gonyautoxins are common toxins of PSP toxins in China sea, which has high toxicity and expensive. In this chapter, molecularly imprinted polymer microspheres (MIPMs) for gonyautoxins 1,4 were prepared using caffeine as the dummy template molecule, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, polyvinyl alcohol as the dispersive reagent,and through method of suspension polymerization. Then the obtained MIP was used as selective sorbent for the solid-phase extraction, to isolate gonyautoxins 1,4 from dinoflagellate Alexandrium minutum and Alexandrium tamarense sample, and enriched the gonyautoxins in sea water, and then validated by HPLC coupled to fluorescence detection. The results showed the MIPMs had a good effect for the enrichment of gonyautoxins in sea water.