| Composited Fe3O4 magnetic material is a new type of functional nanomaterials that have been fully developed in the past ten years.Coating different function groups on the surface of Fe3O4, the Fe3O4 magnetic material show different functions with particles,the applications of super-paramagnetic and functional properties of nanometer Fe3O4 particles.Especially in the environmental monitoring, the application of medicine and biological detection, and separation,enriching and detection of the target substance by using different composited Fe3O4 beads increasingly attracted great attention of researchers. Recently,,the problem of the phthalate ester plasticizer occurred many food safety incidents.There are two major reasons of phthalate ester plasticizer exceed in the food:the one reason is that the high molecular material part of food processing equipment and food packaging materials,in order to good flexibility and other characteristics, often are joined the DBP,DEP asplasticizer.In the process of transportation and storage process,the phthalate ester plasticizers infiltrate and migrate into the harm to human health food,the two reason is part of illegal traders put phthalate ester plasticizers into food as thickening agent and foaming agent Now,it’s great difficulty to separate and inspect in the environment of distribution, because the characteristics of phthalate esters plasticizer. The phthalate esters plasticizer pretreate by liquid-solid extraction,liquid-liquid extraction with high temperature and high pressure, ultrasonic and microwave using or by supercritical fluid extraction.But these methods spend so many organic solvent,polluting the environment,affecting the inspection precision, time consuming, or pretreatment equipment is extremely expensive, processing cost is high. Even the various auxiliary conditions strengthening the efficiency of extraction, some easily to decompose and to degenerat of the matter without method applying these pretreatment methods. Therefore it is necessary to develop a fast,effective and convenient operation for phthalate esters plasticizer effective separation and preconcentration technique, this paper states a way to synthesis of a novel composite Fe3O4 magnetic beads with magnetic separation technology and nanotechnology. Using super paramagnetic material combined with C18,Fe3O4-SiO2-SiO2-C18 Which characteristics magnetic nanoparticles has nonpolar-component adsorption, developing for measuring 6 phthalates -Dibutyl phthalate, Dioctyl Phthalate, Di-N-pentyl phthalate,Diethyl phthalate,Butyl benzyl phthalate, Diallyl phthalate and separation and enrichment of trace exists, and is applied to detect 4 different kinds of liquid food.In this experiment, firstly, the nanometer Fe3O4 prepared by co-precipitation, and then adding CTAB and TEOS coated silicon layer on the nano Fe3O4 particle which is pore structure becauce of the CTAB elution, at last adding the C is With the method for preparing Fe3O4-SiO2-SiO2-C18 particles,the magnetic Fe3O4 nanoparticles size are about 5nm.the surface structure is porous structure,uniform particle size,and strong magnetic response. At the same time the date of Fourier transform infrared analysis showed that the surface of the particles effectively linked C18group.At the same time,2.5mLTEOS and ethanol mixture proportion suitable for 1:5 were found is the best in the the magnetic Fe3O4-SiO2-SiO2-C18 particles preparing process.Excess TEOS causes the particle aggregation and crystallization phenomenon, when it’s 1:3, the particle will appear large-scale aggregation phenomenon, then it’s 1:1,the particle is the emergence of the crystallization phenomenon, appear large micron crystal.Then through the optimization of mobile phase, accelerating the speed of detection,improve the detection limit,so as to establish a simultaneous determination of 6 phthalate esters plasticizer in the high performance liquid chromatographic method.The experiments show that the method has a good degree of separation, the baseline stable,reproducible and can completely satisfy the minimum detection limit to 6 kinds of phthalicacid ester plasticizer for two GB requirements need detection.Finally, the use of new preparation of the particle and the establishment of the new detection method of 6 kinds of phthalate ester plasticizers for detecting and processing. The best separation conditions for the enrichment was 5mg particlebeads, acetonitrile as eluent, the elution dose was 300ul, extraction time was 5min, the elution time was lmin. According to the above conditions respectively on liquor,peanut oil, soy sauce, rice wine. These 4 kinds of food was measured in adding recovery test. In the liquor and peanut oil, in addition to DEHP, other 5 kinds of phthalate ester plasticizers have better recovery rate which can be used to detection and the existence of macromolecule substances in soy sauce and rice wine (protein, starch)cause the recovery rate is poor, also prove that the anti environmental disturbance of particle is poor in complex environment. |
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