Preparation, Characterization And Adsorption Properties Of Phytic Acid Molecularly Imprinted Polymer

Phytic acid known as inositol six phosphoric acid,is generally present in plants in the presence of phytate,which is found in grains,legumes,and oils.At present,for the separation and purification of phytic acid,there are many methods.Because solid phase extraction is simple and easy to operate with low cost,the determination of phytic acid content in vegetable foods in the national standard method of China is based on the pretreatment of anion exchange resin.However,the method of purification of phytic acid by ion exchange is easy to be affected by the coexistence of anions,so that the adsorption capacity of phytic acid is not high.Therefore,it is necessary to develop a highly selective solid phase extraction material for the separation and purification of phytic acid.At home and abroad,the detection methods of phytic acid are mainly focused on ion exchange chromatography,HPLC chromatography and capillary electrophoresis.The method of copper sulfate,precipitation and ferric chloride is a simple and convenient method,but the sensitivity is low.1.The molecularly imprinted polymer(MIPs)were prepared by bulk polymerization using phytic acid(PA)as template molecule,MAA as functional monomer,N,N'-Ethylenebis(acrylamide)as crosslinker,Ammonium persulphate as initiator.2.By infrared spectroscopy,1000 cm^-1near the crest of the apparent weakening in MIPs?NIPs and no-elution NIPs compared with phytic acid standard products maps.This is related to the change of P=O bond in the reaction process.The results showed that phytic acid was successfully implanted into molecular imprinting system.After Elution of phytic acid molecularly imprinted polymer MIPs and MIPs,and blank NIPs contrast,evident in 3400cm^-1near 1550 cm^-1near absorption peaks become sharp and close to the1200cm^-1clear O-H with C=O,but also with P=O to form hydrogen bonds.As MIPs was cleared,This part of the hydrogen bond is recovered from the associated state,and O-H absorption peaks become sharp,that indicate that phytic acid was well cleared.3.The structure of the surface of the molecularly imprinted polymer was further observed by scanning electron microscopy.The results show that the surface of NIPs is smooth and smooth,and the particles are arranged closely,and almost no hole is produced.However,the surface roughness of MIPs is loose and porous,and there are a lot of holes.These holes are exactly the size and size of phytic acid,which shows that the molecular imprinted polymer MIPs has been successfully prepared.4.Through the analysis of particle size,the morphology of phytic acid molecularly imprinted polymer can be preliminarily determined.The morphology of the particles is similar to that of spheres.The size of the MIPs after elution is not obvious compared with the pre elution MIPs.The size of the NIPs after elution is significantly reduced compared with that before the elution of NIPs.5.MIPs adsorption performance were investigated by dynamic adsorption,static adsorption and selective adsorption experiments.The results showed that the adsorption capacity of phytic acid molecularly imprinted polymer was36.8mg/g when p H=2.With the increase of phytic acid concentration,the adsorption capacity of polymer increased first and then tended to be flat.Based on the analysis of the adsorption kinetics of 200min,the adsorption rate of MIPs was very fast at the beginning of the adsorption,and the adsorption capacity increased slowly and remained at a plateau stage.After 5 cycles of adsorption desorption cycles,the performance of MIPs imprinted polymers was stable and could be reused.In terms of selectivity,the adsorption of phytic acid by MIPs was significantly higher than that of inositol.The imprinting factor of phytic acid in the imprinted polymer was 1.70,while that of phytic acid was similar to that of phytic acid,which was about 1.46.Phytic acid molecularly imprinted polymers have strong specificity for the adsorption of phytic acid.6.Through the comparison of pretreatment method and national standard method for the determination of phytic acid,adsorption and desorption of molecular imprinting method has good effect,the spiked recovery rate can reach 99%,at the same time,the national standard method to obtain the value of RSD is about 3 times of MIPs method.The molecular imprinting method with good precision and high accuracy.