Determination Method Research Based On Molecular Imprinting Technology In Seawater And Seafood For Trace Organotin Compounds

Organotin compounds have been used for many years as fungicides, bactericides,pesticides, biocides, and stabilizing agents in catalysts, in anti-fouling paints and coatingsfor the protection of ship hulls. However, they were regarded as the most toxic materialever deliberately introduced into the sea. They could influence sensitive aquaticorganisms in water because of their highly toxic effects at very low concentrations, andendanger human nervous system by the food chain. Therefore, the preconcentration,separation and determination of organotin compounds in sea water and sea food havebecome the popular research in analytical science field.Several analytical methods based on various detectors have been developed todetermine the OTCs. In the present study, It was used LC-MS/MS for detection of traceamounts of TBT in seawater and seafood, because it does not involve a derivatization stepas GC, which leads the loss of analyte, and LC-MS/MS offers a number of advantages,such as more selective separation, element specificity, low detection limits, and highsensitivity, thus making it the most widely used technique for the quantitation of OTCs inthe complex samples.The thesis reported the synthesis of organotin traditional molecularly imprintedpolymer （MIPs） and magnetic molecularly imprinted polymers （Fe₃O₄@MIPs） and theirapplications in preconcentration and separation. The determination of organotin withLC-MS/MS was also discussed. The thesis includes the main contents as follows:1. Using tributyltin chloride as the template molecule, acrylamide as the functionalmonomer, ethylene glycol dimethacrylate as the cross linking monomer and acetonitrileas the solvent, tributyltin chloride traditional molecularly imprinted polymers weresynthesized by the molecular imprinting technology, and the structure of MIPs wascharacterized with transmission electron microscope. We studied the synthesis conditions of MIPs, the adsorption properties and selective recognition of MIPs for tributyltinchloride. The experimental results showed that MIPs had high adsorption capacity andgood selective recognition for tributyltin chloride.2. Fe₃O₄as the support to create surface imprinted materials, and the functionalmonomer acrylamide was grafted to the surface of Fe₃O₄nanospheres in two steps, MIPshells were created from a surface coating formed by copolymerization of vinyl groupswith the functional monomer acrylamide, cross-linking agent ethylene glycoldimethacrylate, initiator azobisisobutyronitrile, and template molecule tributyltinchloride, and the structure of Fe₃O₄@MIPs was characterized with several instruments.We studied the synthesis conditions of Fe₃O₄@MIPs, the adsorption properties andselective recognition of Fe₃O₄@MIPs for tributyltin chloride. Compared with MIPs,Fe₃O₄@MIPs had the greater the amount of adsorption, more significant selectiveadsorption and more simple steps for rapid magnetic separation.3. MIPs and Fe₃O₄@MIPs were used to preconcentrate and separate tributyltinchloride in seawater and sea food, and LC-MS/MS was used to determinate theconcentration of tributyltin chloride. The determinate results showed that the limit ofdetection was respectively0.05μg L^-1and3.0ng g^-1, a linear response was respectively0.1²0μg L^-1and5⁶00ng g^-1and recoveries of tributyltin chloride respectively rangedfrom67.2%to81.1%and75.0%to94.2%in seawater and sea food in MIPs; And thelimit of detection was1.0ng g^-1, a linear response was5¹000ng g^-1and recoveries oftributyltin chloride ranged from78.3%to95.6%in several sea foods in Fe₃O₄@MIPs.However, the latter demonstrated shorter analysis time, low limit of detection, and widerrange of detection for tributyltin chloride. It is better for the determination of organotincompounds in seafood.