Preparation And Application Of Molecularly Imprinted Polymers For Organoarsenic Compounds

Since the antibacterial and growth promoting effects,organoarsenic compounds are widely used in livestock and poultry production as the feed additives,which can not only reduce the production cost,but also kill the intestinal pathogenic bacteria,promote the nutrient absorption and transformation.However,extensive use of the organoarsenic compounds agents can lead to its residues in animal and has the toxic side effects for animals,cause pollution at the same time if converted into inorganic arsenic.Therefore,the development of organoarsenic compounds veterinary drug residue detection method is the focus on food safety.Nowadays,some methods were reported for detecting organoarsenic compounds in foods of animal origin,mainly including the gas chromatography,liquid chromatography,gas chromatography-mass spectrometry,etc.Solid phase extraction(SPE)is commonly used in the sample separation and purification.However,the effect of SPE separation is highly related to the type of filler.The traditional fillers work mainly by the forces of some non-specific adsorption between the adsorbent and the target molecule.Molecular imprinting technology(MIT)is a technique to prepare a polymer with the recognition sites having a predetermined selectivity for the target molecule.Molecularly imprinted solid phase extraction(MISPE),using MIPs as the SPE adsorbents is an effective and accurate tool for separating target compounds from the complex sample constituents for the further analysis.MISPE has advantages over the traditional SPE in that it tends to be the higher selectivity,better stability and lower cost.The main research contents are as follows:1.Synthesizing the novel functional monomer,which is named N,Obismethacryloylethanolamine(NOBE).2.The preparation of molecularly imprinted polymers by a surface molecular imprinting technique with arsanilic acid as the template,silica gel as the carrier,N,Obismethacryloyl ethanolamine as the functional monomer.Under the optimum condition determined by orthogonal design,the MIPs were characterized by infrared spectrum,scanning electron microscope and differential scanning calorimetric,and were proved have a good recognition performance by the selective adsorption experiment.After Scatchard analysis,two classes of binding sites were produced in the resulted MIPs with the dissociation constants of 0.627?g/mL and 3.086?g/mL,and the affinity binding sites of 0.222?g/mg and 0.577?g/mg,respectively.3.The preparation of MIPs by a surface molecular imprinting technique with roxarsone as the template,silica gel as the carrier,N,O-bismethacryloyl ethanolamine as the functional monomer.The MIPs were characterized by infrared spectrum,scanning electron microscope and differential scanning calorimetric,and were proved have a good recognition performance by the selective adsorption experiment.After Scatchard analysis,two classes of binding sites were produced in the resulted MIPs with the dissociation constants of 1.471?g/mL and 3.771?g/m L,and the affinity binding sites of 0.328?g/mg and 0.592?g/mg,respectively.4.ASA-MIPs were used as the adsorption filter to prepare molecular imprinted solid phase extraction column,optimizing the MISPE's solid phased extraction conditions.The result suggests methanol as loading solvent,methanol-water(8:2,v/v)as washing solvent,and methanol-acetic acid(9:1,v/v)as the elution solvent.It is shown that the MIP particles had better extraction selectivity and recovery on ASA.Used in the separation and concentration of ASA in pork tissues,the recovery of MIPSE was 89.0%-90.8%,the capacity of the MISPE cartridge was examined as 714.5?g/g and the MISPE showed a better adsorption efficiency than C18 SPE.This study describes the synthesis of the MIPs specific to organoarsenic compounds with the new functional monomer,with the polymer materials characterized by FTIR,SEM and DSC.MIP is proved to have a good recognition performance by a series of selective absorption experiments.Using organoarsenic compounds imprinted polymer as the solid-phase extraction adsorbent to extract the organoarsenic compounds in the pork samples prior to the chromatographic detection shows a successful result.The recovery hits 91.8%,proving that the procedure was suitable for the selective enrichment and purification of organoarsenic compounds from the complex sample.